The Array.map() is an inbuilt TypeScript function that is used to create a new array with the results of calling a provided function on every element in this array.
Syntax:
array.map(callback[, thisObject])
Parameter: This method accepts two parameters as mentioned above and described below:
- callback : This parameter is the function that produces an element of the new Array from an element of the current one.
- thisObject : This parameter is the Object to use as this when executing callback.
Return Value: This method returns the created array.
Below examples illustrate the Array map() method in TypeScript.
Example 1:
JavaScript
// language is TypeScript // Driver code
var arr = [ 11, 89, 23, 7, 98 ];
// use of map() method
var val = arr.map(Math.log)
// printing element
console.log( val );
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Output:
[ 2.3978952727983707, 4.48863636973214, 3.1354942159291497, 1.9459101490553132, 4.584967478670572 ]
Example 2:
JavaScript
// language is TypeScript // Driver code
var arr = [2, 5, 6, 3, 8, 9];
// use of map() method
var newArr = arr.map( function (val, index){
// printing element
console.log( "key : " ,index, "value : " ,val*val);
})
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Output:
key : 0 value : 4 key : 1 value : 25 key : 2 value : 36 key : 3 value : 9 key : 4 value : 64 key : 5 value : 81