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# Object Functions
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Object manipulation functions for property access, modification, merging, and transformation including deep operations and property path handling.
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## Capabilities
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### Property Access
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Functions for getting and checking object properties, including deep property paths.
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```javascript { .api }
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/**
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 * Gets the value at path of object
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 * @param {Object} object - The object to query
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 * @param {Array|string} path - The path of the property to get
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 * @param {*} defaultValue - The value returned for undefined resolved values
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 * @returns {*} Returns the resolved value
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 */
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function get(object, path, defaultValue);
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/**
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 * Checks if path is a direct property of object
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 * @param {Object} object - The object to query
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 * @param {Array|string} path - The path to check
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 * @returns {boolean} Returns true if path exists, else false
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 */
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function has(object, path);
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/**
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 * Checks if path is a direct or inherited property of object
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 * @param {Object} object - The object to query
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 * @param {Array|string} path - The path to check
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 * @returns {boolean} Returns true if path exists, else false
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 */
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function hasIn(object, path);
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/**
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 * Gets the value at path of object. If the resolved value is a function it's invoked
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 * @param {Object} object - The object to query
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 * @param {Array|string} path - The path of the property to get
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 * @param {...*} args - The arguments to invoke the function with
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 * @returns {*} Returns the resolved value
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 */
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function result(object, path, ...args);
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```
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### Property Modification
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Functions for setting, updating, and removing object properties.
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```javascript { .api }
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/**
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 * Sets the value at path of object
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 * @param {Object} object - The object to modify
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 * @param {Array|string} path - The path of the property to set
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 * @param {*} value - The value to set
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 * @returns {Object} Returns object
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 */
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function set(object, path, value);
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/**
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 * Like set but accepts customizer which is invoked to produce the objects of path
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 * @param {Object} object - The object to modify
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 * @param {Array|string} path - The path of the property to set
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 * @param {*} value - The value to set
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 * @param {Function} customizer - The function to customize assigned values
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 * @returns {Object} Returns object
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 */
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function setWith(object, path, value, customizer);
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/**
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 * Removes the property at path of object
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 * @param {Object} object - The object to modify
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 * @param {Array|string} path - The path of the property to unset
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 * @returns {boolean} Returns true if the property is deleted, else false
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 */
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function unset(object, path);
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/**
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 * Sets the value at path of object to the result of updater
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 * @param {Object} object - The object to modify
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 * @param {Array|string} path - The path of the property to update
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 * @param {Function} updater - The function to produce the updated value
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 * @returns {Object} Returns object
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 */
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function update(object, path, updater);
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/**
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 * Like update but accepts customizer which is invoked to produce the objects of path
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 * @param {Object} object - The object to modify
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 * @param {Array|string} path - The path of the property to update
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 * @param {Function} updater - The function to produce the updated value
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 * @param {Function} customizer - The function to customize assigned values
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 * @returns {Object} Returns object
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 */
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function updateWith(object, path, updater, customizer);
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```
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### Object Keys and Values
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Functions for extracting keys, values, and key-value pairs from objects.
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```javascript { .api }
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/**
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 * Creates an array of the own enumerable property names of object
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 * @param {Object} object - The object to query
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 * @returns {Array} Returns the array of property names
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 */
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function keys(object);
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/**
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 * Creates an array of the own and inherited enumerable property names of object
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 * @param {Object} object - The object to query
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 * @returns {Array} Returns the array of property names
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 */
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function keysIn(object);
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/**
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 * Creates an array of the own enumerable string keyed property values of object
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 * @param {Object} object - The object to query
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 * @returns {Array} Returns the array of property values
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 */
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function values(object);
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/**
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 * Creates an array of the own and inherited enumerable string keyed property values of object
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 * @param {Object} object - The object to query
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 * @returns {Array} Returns the array of property values
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 */
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function valuesIn(object);
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/**
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 * Creates an array of own enumerable string keyed-value pairs for object
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 * @param {Object} object - The object to query
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 * @returns {Array} Returns the key-value pairs
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 */
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function toPairs(object);
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/**
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 * Creates an array of own and inherited enumerable string keyed-value pairs for object
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 * @param {Object} object - The object to query
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 * @returns {Array} Returns the key-value pairs
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 */
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function toPairsIn(object);
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/**
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 * Alias for toPairs
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 * @param {Object} object - The object to query
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 * @returns {Array} Returns the key-value pairs
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 */
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function entries(object);
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/**
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 * Alias for toPairsIn
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 * @param {Object} object - The object to query
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 * @returns {Array} Returns the key-value pairs
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 */
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function entriesIn(object);
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```
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### Object Assignment and Merging
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Functions for copying properties between objects and merging objects.
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```javascript { .api }
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/**
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 * Assigns own enumerable string keyed properties of source objects to the destination object
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @returns {Object} Returns object
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 */
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function assign(object, ...sources);
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/**
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 * Like assign but iterates over own and inherited source properties
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @returns {Object} Returns object
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 */
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function assignIn(object, ...sources);
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/**
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 * Like assign but accepts customizer which is invoked to produce the assigned values
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @param {Function} customizer - The function to customize assigned values
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 * @returns {Object} Returns object
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 */
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function assignWith(object, ...sources, customizer);
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/**
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 * Like assignIn but accepts customizer which is invoked to produce the assigned values
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @param {Function} customizer - The function to customize assigned values
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 * @returns {Object} Returns object
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 */
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function assignInWith(object, ...sources, customizer);
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/**
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 * Alias for assignIn
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @returns {Object} Returns object
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 */
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function extend(object, ...sources);
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/**
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 * Alias for assignInWith
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @param {Function} customizer - The function to customize assigned values
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 * @returns {Object} Returns object
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 */
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function extendWith(object, ...sources, customizer);
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/**
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 * Recursively merges own and inherited enumerable string keyed properties of source objects
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @returns {Object} Returns object
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 */
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function merge(object, ...sources);
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/**
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 * Like merge but accepts customizer which is invoked to produce the merged values
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @param {Function} customizer - The function to customize assigned values
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 * @returns {Object} Returns object
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 */
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function mergeWith(object, ...sources, customizer);
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```
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### Object Defaults
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Functions for setting default property values.
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```javascript { .api }
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/**
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 * Assigns own and inherited enumerable string keyed properties of source objects to the destination object for all destination properties that resolve to undefined
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @returns {Object} Returns object
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 */
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function defaults(object, ...sources);
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/**
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 * Like defaults but recursively assigns default properties
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 * @param {Object} object - The destination object
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 * @param {...Object} sources - The source objects
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 * @returns {Object} Returns object
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 */
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function defaultsDeep(object, ...sources);
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```
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### Object Property Selection
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Functions for selecting and omitting object properties.
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```javascript { .api }
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/**
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 * Creates an object composed of the picked object properties
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 * @param {Object} object - The source object
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 * @param {...(string|string[])} paths - The property paths to pick
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 * @returns {Object} Returns the new object
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 */
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function pick(object, ...paths);
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/**
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 * Creates an object composed of the object properties predicate returns truthy for
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 * @param {Object} object - The source object
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 * @param {Function} predicate - The function invoked per property
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 * @returns {Object} Returns the new object
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 */
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function pickBy(object, predicate);
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/**
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 * Creates an object composed of the own and inherited enumerable property paths of object that are not omitted
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 * @param {Object} object - The source object
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 * @param {...(string|string[])} paths - The property paths to omit
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 * @returns {Object} Returns the new object
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 */
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function omit(object, ...paths);
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/**
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 * The opposite of pickBy; creates an object composed of the own and inherited enumerable string keyed properties of object that predicate doesn't return truthy for
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 * @param {Object} object - The source object
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 * @param {Function} predicate - The function invoked per property
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 * @returns {Object} Returns the new object
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 */
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function omitBy(object, predicate);
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/**
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 * Creates an array of values corresponding to paths of object
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 * @param {Object} object - The object to query
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 * @param {...(string|string[])} paths - The property paths to get
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 * @returns {Array} Returns the array of property values
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 */
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function at(object, ...paths);
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```
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### Object Iteration
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Functions for iterating over object properties.
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```javascript { .api }
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/**
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 * Iterates over own enumerable string keyed properties of an object and invokes iteratee for each property
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 * @param {Object} object - The object to iterate over
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 * @param {Function} iteratee - The function invoked per iteration
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 * @returns {Object} Returns object
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 */
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function forOwn(object, iteratee);
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/**
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 * Like forOwn but iterates over properties in the opposite order
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 * @param {Object} object - The object to iterate over
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 * @param {Function} iteratee - The function invoked per iteration
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 * @returns {Object} Returns object
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 */
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function forOwnRight(object, iteratee);
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/**
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 * Iterates over own and inherited enumerable string keyed properties of an object and invokes iteratee for each property
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 * @param {Object} object - The object to iterate over
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 * @param {Function} iteratee - The function invoked per iteration
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 * @returns {Object} Returns object
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 */
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function forIn(object, iteratee);
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/**
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 * Like forIn but iterates over properties in the opposite order
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 * @param {Object} object - The object to iterate over
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 * @param {Function} iteratee - The function invoked per iteration
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 * @returns {Object} Returns object
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 */
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function forInRight(object, iteratee);
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```
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### Object Search
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Functions for finding properties within objects.
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```javascript { .api }
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/**
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 * Returns the key of the first element predicate returns truthy for
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 * @param {Object} object - The object to inspect
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 * @param {Function} predicate - The function invoked per iteration
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 * @returns {string|undefined} Returns the key of the matched element, else undefined
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 */
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function findKey(object, predicate);
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/**
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 * Like findKey but iterates over the object's properties in the opposite order
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 * @param {Object} object - The object to inspect
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 * @param {Function} predicate - The function invoked per iteration
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 * @returns {string|undefined} Returns the key of the matched element, else undefined
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 */
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function findLastKey(object, predicate);
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```
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### Object Key/Value Transformation
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Functions for transforming object keys and values.
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```javascript { .api }
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/**
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 * Creates an object with the same values as object and keys generated by running each own enumerable string keyed property of object thru iteratee
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 * @param {Object} object - The object to iterate over
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 * @param {Function} iteratee - The function invoked per iteration
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 * @returns {Object} Returns the new mapped object
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 */
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function mapKeys(object, iteratee);
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/**
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 * Creates an object with the same keys as object and values generated by running each own enumerable string keyed property of object thru iteratee
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 * @param {Object} object - The object to iterate over
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 * @param {Function} iteratee - The function invoked per iteration
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 * @returns {Object} Returns the new mapped object
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 */
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function mapValues(object, iteratee);
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/**
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 * An alternative to _.reduce; this method transforms object to a new accumulator object
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 * @param {Array|Object} object - The object to iterate over
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 * @param {Function} iteratee - The function invoked per iteration
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 * @param {*} accumulator - The custom accumulator value
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 * @returns {*} Returns the accumulated value
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 */
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function transform(object, iteratee, accumulator);
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```
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### Object Inversion
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Functions for inverting object key-value relationships.
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```javascript { .api }
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/**
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 * Creates an object composed of the inverted keys and values of object
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 * @param {Object} object - The object to invert
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 * @returns {Object} Returns the new inverted object
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 */
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function invert(object);
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/**
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 * Like invert but the inverted object is generated from the results of running each element of object thru iteratee
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 * @param {Object} object - The object to invert
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 * @param {Function} iteratee - The function invoked per iteration
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 * @returns {Object} Returns the new inverted object
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 */
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function invertBy(object, iteratee);
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```
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### Object Function Properties
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Functions for working with function properties of objects.
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```javascript { .api }
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/**
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 * Creates an array of function property names from own enumerable properties of object
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 * @param {Object} object - The object to inspect
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 * @returns {Array} Returns the function names
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 */
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function functions(object);
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/**
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 * Creates an array of function property names from own and inherited enumerable properties of object
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 * @param {Object} object - The object to inspect
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 * @returns {Array} Returns the function names
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 */
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function functionsIn(object);
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/**
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 * Invokes the method at path of object
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 * @param {Object} object - The object to query
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 * @param {Array|string} path - The path of the method to invoke
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 * @param {...*} args - The arguments to invoke the method with
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 * @returns {*} Returns the result of the invoked method
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 */
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function invoke(object, path, ...args);
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```
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### Object Creation
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Functions for creating new objects.
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```javascript { .api }
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/**
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 * Creates an object that inherits from the prototype object
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 * @param {Object} prototype - The object to inherit from
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 * @param {Object} properties - The properties to assign to the object
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 * @returns {Object} Returns the new object
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 */
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function create(prototype, properties);
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```
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## Usage Examples
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### Property Access and Modification
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```javascript
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import { get, set, has, unset } from "lodash-es";
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const user = {
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  name: "Alice",
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  profile: {
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    age: 25,
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    settings: {
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      theme: "dark",
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      notifications: true
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    }
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  }
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};
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// Get nested properties
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const age = get(user, "profile.age"); // 25
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const theme = get(user, "profile.settings.theme", "light"); // "dark"
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const missing = get(user, "profile.bio", "No bio"); // "No bio"
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// Check property existence
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const hasAge = has(user, "profile.age"); // true
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const hasBio = has(user, "profile.bio"); // false
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// Set nested properties
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set(user, "profile.bio", "Software engineer");
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set(user, "profile.settings.language", "en");
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// Remove properties
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unset(user, "profile.settings.notifications");
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```
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### Object Merging and Assignment
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```javascript
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import { assign, merge, defaults, pick, omit } from "lodash-es";
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const target = { a: 1, b: 2 };
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const source1 = { b: 3, c: 4 };
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const source2 = { c: 5, d: 6 };
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// Shallow assignment (modifies target)
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assign(target, source1, source2); // { a: 1, b: 3, c: 5, d: 6 }
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// Deep merging
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const obj1 = { user: { name: "Alice", age: 25 } };
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const obj2 = { user: { age: 26, city: "NYC" } };
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const merged = merge({}, obj1, obj2); // { user: { name: "Alice", age: 26, city: "NYC" } }
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// Set defaults
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const config = { timeout: 1000 };
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defaults(config, { timeout: 5000, retries: 3 }); // { timeout: 1000, retries: 3 }
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// Pick and omit properties
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const data = { name: "Alice", age: 25, password: "secret", email: "alice@example.com" };
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const publicData = omit(data, ["password"]); // { name: "Alice", age: 25, email: "alice@example.com" }
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const basicInfo = pick(data, ["name", "age"]); // { name: "Alice", age: 25 }
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```
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### Object Transformation
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```javascript
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import { mapKeys, mapValues, transform, keys, values, toPairs } from "lodash-es";
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const scores = { alice: 85, bob: 92, charlie: 78 };
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// Transform keys
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const upperKeys = mapKeys(scores, (value, key) => key.toUpperCase());
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// { ALICE: 85, BOB: 92, CHARLIE: 78 }
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// Transform values
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const percentages = mapValues(scores, score => `${score}%`);
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// { alice: "85%", bob: "92%", charlie: "78%" }
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// Custom transformation
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const result = transform(
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  scores,
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  (acc, score, name) => {
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    if (score >= 80) {
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      acc.push({ name, score, grade: "A" });
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    }
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  },
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  []
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);
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// [{ name: "alice", score: 85, grade: "A" }, { name: "bob", score: 92, grade: "A" }]
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// Extract keys, values, and pairs
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const names = keys(scores); // ["alice", "bob", "charlie"]
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const scoreValues = values(scores); // [85, 92, 78]
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const pairs = toPairs(scores); // [["alice", 85], ["bob", 92], ["charlie", 78]]
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```
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### Advanced Object Operations
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```javascript
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import { findKey, invert, functions, invoke } from "lodash-es";
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const users = {
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  alice: { age: 25, active: true },
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  bob: { age: 30, active: false },
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  charlie: { age: 35, active: true }
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};
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// Find key by predicate
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const firstActive = findKey(users, { active: true }); // "alice"
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const over30 = findKey(users, user => user.age > 30); // "charlie"
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// Invert object
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const ageToName = invert(mapValues(users, "age")); // { "25": "alice", "30": "bob", "35": "charlie" }
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// Work with function properties
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const calculator = {
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  add: (a, b) => a + b,
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  multiply: (a, b) => a * b,
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  name: "Calculator"
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};
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const methods = functions(calculator); // ["add", "multiply"]
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const result = invoke(calculator, "add", 5, 3); // 8
579
```