Description

The map() method is used run a function on every item in the array and returns the results in an array.

This method has the form:

Array.map(callback[, thisArg])

Parameter	Description
callback	(required) Specifies the function that produces an element of the new Array from an element of the current one The callback is invoked with three arguments: 1. the value of the element, 2. the index of the element, and 3. the Array object being traversed
thisArg	(optional) Specifies the object to use as this when executing callback If a this parameter is specified, it will be used as the this for each invocation of the callback. If it is not provided, or is null, the global object associated with callback is used instead.

Note: The specified callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.

Examples

The following example shows the basic use of this method.

<script>
function calculateSquare(element, index, array) {
  return (element * element);
}

var squareList = [1, 2, 3, 4, 5].map(calculateSquare);
document.write("squareList = " + squareList);
</script>

This produces the following result:

Browser Support

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Version Information

This form was added in version: 1.6