- Javascript Basics Tutorial
- Javascript - Home
- JavaScript - Overview
- JavaScript - Features
- JavaScript - Enabling
- JavaScript - Placement
- JavaScript - Syntax
- JavaScript - Hello World
- JavaScript - Console.log()
- JavaScript - Comments
- JavaScript - Variables
- JavaScript - let Statement
- JavaScript - Constants
- JavaScript - Data Types
- JavaScript - Type Conversions
- JavaScript - Strict Mode
- JavaScript - Reserved Keywords
- JavaScript Operators
- JavaScript - Operators
- JavaScript - Arithmetic Operators
- JavaScript - Comparison Operators
- JavaScript - Logical Operators
- JavaScript - Bitwise Operators
- JavaScript - Assignment Operators
- JavaScript - Conditional Operators
- JavaScript - typeof Operator
- JavaScript - Nullish Coalescing Operator
- JavaScript - Delete Operator
- JavaScript - Comma Operator
- JavaScript - Grouping Operator
- JavaScript - Yield Operator
- JavaScript - Spread Operator
- JavaScript - Exponentiation Operator
- JavaScript - Operator Precedence
- JavaScript Control Flow
- JavaScript - If...Else
- JavaScript - While Loop
- JavaScript - For Loop
- JavaScript - For...in
- Javascript - For...of
- JavaScript - Loop Control
- JavaScript - Break Statement
- JavaScript - Continue Statement
- JavaScript - Switch Case
- JavaScript - User Defined Iterators
- JavaScript Functions
- JavaScript - Functions
- JavaScript - Function Expressions
- JavaScript - Function Parameters
- JavaScript - Default Parameters
- JavaScript - Function() Constructor
- JavaScript - Function Hoisting
- JavaScript - Self-Invoking Functions
- JavaScript - Arrow Functions
- JavaScript - Function Invocation
- JavaScript - Function call()
- JavaScript - Function apply()
- JavaScript - Function bind()
- JavaScript - Closures
- JavaScript - Variable Scope
- JavaScript - Global Variables
- JavaScript - Smart Function Parameters
- JavaScript Objects
- JavaScript - Number
- JavaScript - Boolean
- JavaScript - Strings
- JavaScript - Arrays
- JavaScript - Date
- JavaScript - Math
- JavaScript - RegExp
- JavaScript - Symbol
- JavaScript - Sets
- JavaScript - WeakSet
- JavaScript - Maps
- JavaScript - WeakMap
- JavaScript - Iterables
- JavaScript - Reflect
- JavaScript - TypedArray
- JavaScript - Template Literals
- JavaScript - Tagged Templates
- Object Oriented JavaScript
- JavaScript - Objects
- JavaScript - Classes
- JavaScript - Object Properties
- JavaScript - Object Methods
- JavaScript - Static Methods
- JavaScript - Display Objects
- JavaScript - Object Accessors
- JavaScript - Object Constructors
- JavaScript - Native Prototypes
- JavaScript - ES5 Object Methods
- JavaScript - Encapsulation
- JavaScript - Inheritance
- JavaScript - Abstraction
- JavaScript - Polymorphism
- JavaScript - Destructuring Assignment
- JavaScript - Object Destructuring
- JavaScript - Array Destructuring
- JavaScript - Nested Destructuring
- JavaScript - Optional Chaining
- JavaScript - Global Object
- JavaScript - Mixins
- JavaScript - Proxies
- JavaScript Versions
- JavaScript - History
- JavaScript - Versions
- JavaScript - ES5
- JavaScript - ES6
- ECMAScript 2016
- ECMAScript 2017
- ECMAScript 2018
- ECMAScript 2019
- ECMAScript 2020
- ECMAScript 2021
- ECMAScript 2022
- JavaScript Cookies
- JavaScript - Cookies
- JavaScript - Cookie Attributes
- JavaScript - Deleting Cookies
- JavaScript Browser BOM
- JavaScript - Browser Object Model
- JavaScript - Window Object
- JavaScript - Document Object
- JavaScript - Screen Object
- JavaScript - History Object
- JavaScript - Navigator Object
- JavaScript - Location Object
- JavaScript - Console Object
- JavaScript Web APIs
- JavaScript - Web API
- JavaScript - History API
- JavaScript - Storage API
- JavaScript - Forms API
- JavaScript - Worker API
- JavaScript - Fetch API
- JavaScript - Geolocation API
- JavaScript Events
- JavaScript - Events
- JavaScript - DOM Events
- JavaScript - addEventListener()
- JavaScript - Mouse Events
- JavaScript - Keyboard Events
- JavaScript - Form Events
- JavaScript - Window/Document Events
- JavaScript - Event Delegation
- JavaScript - Event Bubbling
- JavaScript - Event Capturing
- JavaScript - Custom Events
- JavaScript Error Handling
- JavaScript - Error Handling
- JavaScript - try...catch
- JavaScript - Debugging
- JavaScript - Custom Errors
- JavaScript - Extending Errors
- JavaScript Important Keywords
- JavaScript - this Keyword
- JavaScript - void Keyword
- JavaScript - new Keyword
- JavaScript - var Keyword
- JavaScript HTML DOM
- JavaScript - HTML DOM
- JavaScript - DOM Methods
- JavaScript - DOM Document
- JavaScript - DOM Elements
- JavaScript - DOM Forms
- JavaScript - Changing HTML
- JavaScript - Changing CSS
- JavaScript - DOM Animation
- JavaScript - DOM Navigation
- JavaScript - DOM Collections
- JavaScript - DOM Node Lists
- JavaScript Miscellaneous
- JavaScript - Ajax
- JavaScript - Async Iteration
- JavaScript - Atomics Objects
- JavaScript - Rest Parameter
- JavaScript - Page Redirect
- JavaScript - Dialog Boxes
- JavaScript - Page Printing
- JavaScript - Validations
- JavaScript - Animation
- JavaScript - Multimedia
- JavaScript - Image Map
- JavaScript - Browsers
- JavaScript - JSON
- JavaScript - Multiline Strings
- JavaScript - Date Formats
- JavaScript - Get Date Methods
- JavaScript - Set Date Methods
- JavaScript - Modules
- JavaScript - Dynamic Imports
- JavaScript - BigInt
- JavaScript - Blob
- JavaScript - Unicode
- JavaScript - Shallow Copy
- JavaScript - Call Stack
- JavaScript - Reference Type
- JavaScript - IndexedDB
- JavaScript - Clickjacking Attack
- JavaScript - Currying
- JavaScript - Graphics
- JavaScript - Canvas
- JavaScript - Debouncing
- JavaScript - Performance
- JavaScript - Style Guide
- JavaScript Useful Resources
- JavaScript - Questions And Answers
- JavaScript - Quick Guide
- JavaScript - Functions
- JavaScript - Resources
JavaScript - Array map() Method
Description
Javascript array map() method creates a new array with the results of calling a provided function on every element in this array.
Syntax
Its syntax is as follows −
array.map(callback[, thisObject]);
Parameter Details
callback − Function that produces an element of the new Array from an element of the current one.
thisObject − Object to use as this when executing callback.
Return Value
Returns the created array.
Compatibility
This method is a JavaScript extension to the ECMA-262 standard; as such it may not be present in other implementations of the standard. To make it work, you need to add the following code at the top of your script.
if (!Array.prototype.map) { Array.prototype.map = function(fun /*, thisp*/) { var len = this.length; if (typeof fun != "function") throw new TypeError(); var res = new Array(len); var thisp = arguments[1]; for (var i = 0; i < len; i++) { if (i in this) res[i] = fun.call(thisp, this[i], i, this); } return res; }; }
Example
Try the following example.
<html> <head> <title>JavaScript Array map Method</title> </head> <body> <script type = "text/javascript"> if (!Array.prototype.map) { Array.prototype.map = function(fun /*, thisp*/) { var len = this.length; if (typeof fun != "function") throw new TypeError(); var res = new Array(len); var thisp = arguments[1]; for (var i = 0; i < len; i++) { if (i in this) res[i] = fun.call(thisp, this[i], i, this); } return res; }; } var numbers = [1, 4, 9]; var roots = numbers.map(Math.sqrt); document.write("roots is : " + roots ); </script> </body> </html>
Output
roots is : 1,2,3
javascript_arrays_object.htm
Advertisements