Description map() creates a new array from calling a function for every array element. map() does not execute the function for empty elements. map() does not change the original array.

This tutorial shows you how to use the JavaScript Array map() method to transform elements in an array based on a provided function.

Dec 8, 2025 · The Map object holds key-value pairs and remembers the original insertion order of the keys. Any value (both objects and primitive values) may be used as either a key or a value.

Jul 11, 2025 · The map () method is an ES5 feature that creates a new array by applying a function to each element of the original array. It skips empty elements and does not modify the original array.

Mar 31, 2021 · The callback function() is called on each array element, and the map() method always passes the current element, the index of the current element, and the whole array object to it.

The Map.groupBy() method groups elements of an object according to string values returned from a callback function. The Map.groupBy() method does not change the original object.

Feb 15, 2024 · JavaScript's map method, introduced in ECMAScript 5, is a fundamental tool for array manipulation and transformation. This method is versatile and simple, and has become a staple in …

Dec 18, 2024 · What is JavaScript’s .map()? JavaScript’s .map() method creates a new array by applying a callback function to each element of the original array. The method transforms each value …