lodash.unset

The lodash method _.unset exported as a standalone Node.js module for removing object properties at specified paths. This package provides a focused, dependency-free way to safely remove nested properties from objects using flexible path notation.

Package Information

• Package Name: lodash.unset
• Package Type: npm
• Language: JavaScript
• Installation: npm install lodash.unset

Core Imports

var unset = require('lodash.unset');

Note: This package is built for CommonJS and does not provide native ES6 module exports.

Basic Usage

var unset = require('lodash.unset');

// Create a test object
var object = { 'a': [{ 'b': { 'c': 7 } }] };

// Remove nested property using dot notation
var result = unset(object, 'a[0].b.c');
console.log(result);  // => true
console.log(object);  // => { 'a': [{ 'b': {} }] }

// Remove property using array path
var object2 = { 'a': [{ 'b': { 'c': 7 } }] };
var result2 = unset(object2, ['a', '0', 'b', 'c']);
console.log(result2); // => true
console.log(object2); // => { 'a': [{ 'b': {} }] }

Capabilities

Property Removal

Removes the property at the specified path of an object. The method mutates the original object and supports various path formats.

/**
 * Removes the property at `path` of `object`.
 * 
 * Note: This method mutates `object`.
 * 
 * @param {Object} object The object to modify.
 * @param {Array|string} path The path of the property to unset.
 * @returns {boolean} Returns `true` if the property is deleted, else `false`.
 */
function unset(object, path);

Parameters:

• object (Object): The object to modify. Can be null or undefined (treated as no-op).
• path (Array|string): The path of the property to unset. Supports multiple formats:
  • Dot notation: 'a.b.c'
  • Bracket notation: 'a[0].b.c', 'a["key"].b'
  • Mixed notation: 'a[0].b["key"].c'
  • Array path: ['a', 0, 'b', 'key', 'c']

Returns:

• boolean: Returns true if the property is deleted, false if the property doesn't exist or deletion fails.

Behavior:

• Mutates original object: The function modifies the input object directly.
• Safe with null/undefined: Returns true for null or undefined objects (no-op).
• Handles non-existent paths: Returns false for paths that don't exist.
• Path parsing: Supports escaped characters in quoted strings within bracket notation.
• Array index handling: Numeric strings in paths are treated as array indices when appropriate.

Usage Examples:

var unset = require('lodash.unset');

// Dot notation
var obj1 = { a: { b: { c: 42 } } };
unset(obj1, 'a.b.c');
// => true, obj1 is now { a: { b: {} } }

// Bracket notation with array indices
var obj2 = { users: [{ name: 'Alice', age: 30 }] };
unset(obj2, 'users[0].age');
// => true, obj2 is now { users: [{ name: 'Alice' }] }

// Array path format
var obj3 = { data: { items: [{ id: 1, value: 'test' }] } };
unset(obj3, ['data', 'items', 0, 'value']);
// => true, obj3 is now { data: { items: [{ id: 1 }] } }

// Mixed notation with quoted keys
var obj4 = { 'special-key': { 'another key': 'value' } };
unset(obj4, '["special-key"]["another key"]');
// => true, obj4 is now { 'special-key': {} }

// Handle non-existent paths gracefully
var obj5 = { a: 1 };
unset(obj5, 'b.c.d');
// => false, obj5 remains { a: 1 }

// Handle null/undefined objects
unset(null, 'any.path');
// => true (no-op)
unset(undefined, 'any.path');
// => true (no-op)

Path Resolution Details

The unset function supports sophisticated path parsing:

Supported Path Formats

1. Dot Notation: 'property.nested.deep'
2. Bracket Notation: 'property["key"]', 'property[0]'
3. Mixed Notation: 'property[0].nested["key"]'
4. Array Paths: ['property', 0, 'nested', 'key']

Special Character Handling

• Escaped Characters: Supports escaped characters in quoted strings ('key["with \"quotes\""]')
• Numeric Indices: Automatically treats numeric strings as array indices
• Special Keys: Handles property names with spaces, hyphens, and special characters

Edge Cases

• Empty Paths: Empty strings or empty arrays are treated as no-op
• Invalid Objects: Non-object targets return false
• Prototype Properties: Only removes own properties, not inherited ones
• Non-configurable Properties: May return false for non-configurable properties