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# lodash.ismap
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The lodash.ismap package provides the `_.isMap` utility method as a standalone Node.js module. It checks if a value is a Map object using internal object type checking mechanisms, offering cross-environment compatibility and optimal performance.
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## Package Information
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- **Package Name**: lodash.ismap
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- **Package Type**: npm
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- **Language**: JavaScript
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- **Installation**: `npm install lodash.ismap`
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## Core Imports
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```javascript
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var isMap = require('lodash.ismap');
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```
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## Basic Usage
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```javascript
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var isMap = require('lodash.ismap');
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// Check if value is a Map
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isMap(new Map);
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// => true
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isMap(new WeakMap);
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// => false
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isMap({});
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// => false
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isMap([1, 2, 3]);
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// => false
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isMap(null);
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// => false
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```
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## Capabilities
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### Map Type Checking
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Checks if a value is classified as a Map object with cross-environment compatibility.
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```javascript { .api }
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/**
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 * Checks if `value` is classified as a `Map` object.
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 *
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 * @param {*} value The value to check.
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 * @returns {boolean} Returns `true` if `value` is a map, else `false`.
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 */
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function isMap(value);
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```
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**Parameters:**
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- `value` (*): The value to check
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**Returns:**
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- `boolean`: Returns `true` if `value` is a map, else `false`
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**Implementation Details:**
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The function uses two different strategies based on the environment:
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1. **Node.js Environment**: Uses native `util.isMap` for optimal performance when available
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2. **Browser/General Environment**: Falls back to object type checking using `Object.prototype.toString`
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The implementation handles cross-browser compatibility issues and provides accurate Map detection across different JavaScript environments, including:
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- Native Map support in modern browsers
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- IE 11 compatibility issues  
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- Node.js optimizations
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- Host object detection in older IE versions
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**Usage Examples:**
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```javascript  
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var isMap = require('lodash.ismap');
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// Standard Map object
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var myMap = new Map([['key1', 'value1'], ['key2', 'value2']]);
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console.log(isMap(myMap)); // => true
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// WeakMap (not a Map)
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var myWeakMap = new WeakMap();
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console.log(isMap(myWeakMap)); // => false
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// Plain objects
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console.log(isMap({})); // => false
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console.log(isMap({ a: 1 })); // => false
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// Arrays
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console.log(isMap([])); // => false
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console.log(isMap([1, 2, 3])); // => false
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// Primitives
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console.log(isMap(null)); // => false
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console.log(isMap(undefined)); // => false
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console.log(isMap(42)); // => false
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console.log(isMap('string')); // => false
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console.log(isMap(true)); // => false
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// Edge cases
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console.log(isMap(new Set())); // => false
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console.log(isMap(new Date())); // => false
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console.log(isMap(/regex/)); // => false
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```