# Array

## JavaScript Array, map, valueOf,indexOf and lastIndexOf

The map function of a JavaScript array applies a certain method to all elements and creates an array. Example 1 The following method call will change all values to positive function f() { var a = Array(1,2,-3,4); var b = a.map(Math.abs); } Output: a=1,2,-3,4 b=1,2,3,4 Example 2 The following method call will…

## Array functions concat, copyWithin, every, fill, filter, find, forEach

1. concat function merges arrays and returns the combined array Example 1 var a = Array(1, 2, 3); var b = Array(4, 5, 6); var c=Array(7,8,9); var d = a.concat(b, c); a=1,2,3 b=4,5,6 c=7,8,9 d=1,2,3,4,5,6,7,8,9 concat does not modify the original arrays and we can concat as many arrays as…

## Array functions toString, join, pop, push, shift and unshift

The toString function converts an array to a string by concatenation elements with commas in between. toString method Example 1: var a=Array(1,2,3); var s=a.toString(); s is “1,2,3” Example 2: var a = Array(1, “apple”, Math,Math.sqrt); var s = a.toString(); s is “1,apple,[object Math],function sqrt() { [native code] }” join method…

## Splice function in JavaScript

The splice function in JavaScript is used for adding, removing and returning elements from an array. Let us suppose we have an array var a=new Array(1,2,3,4,5); Splice with one parameter: This returns the elements of the array starting at the parameter. var b=a.splice(0); b=1,2,3,4,5. a=var b=a.splice(2): b=3,4,5 a=1,2 Splice with 2…

## Sort Function in JavaScript Arrays

The sort function in JavaScript Arrays allows performs sorting of array elements. Like all of JavaScript this function is remarkably flexible as well. Let us say we want to sort an array. var a=Array(4,5,3,-2); To sort you call a.sort(); This will sort the array numerically. -2,3,4,5 To change the sorting mode we…