In JavaScript, we can access an array element as in other programming languages like C, C++, Java etc. Also, there is a method called splice() in JavaScript, by which an array can be removed or replaced by another element for an index. So to move an array element from one array position to another we can splice() method or we can simply use array indexing ([]).
Example 1: Simple code for moving an array element from one array position to another, without using any functions.
javascript
let arr = ["C++", "Java", "JS", "Python"];console.log("Original array: " + arr);// Position where from the element is // going to move here 'python' is moved let x = 3;// Position at which element is to be // moved here 'python' is moved to // index 1 which is index of 'Java'let pos = 1;// Store the moved element in a temp // variablelet temp = arr[x];// shift elements forward let i;for (i = x; i >= pos; i--) { arr[i] = arr[i - 1];}// Insert moved element at position arr[pos] = temp;console.log("After move: " + arr); |
Output
Original array: C++,Java,JS,Python After move: C++,Python,Java,JS
Example 2: Now move an array element from one array position to another using a function.
javascript
let arr = ["C++ ", "Java ", "JS ", "Ruby ", "Python "];// Print the array before movingconsole.log("Original array: " + arr);// Position where from the element is // going to move here 'Ruby' is moved let moveEle = 3;// Position at which element is to be moved // here 'Ruby' is moved to index 1 which is // index of 'Java'let moveToIndx = 1;// If actual index of moved element is // less than 0 when 'moveEle += array size'while (moveEle < 0) { moveEle += arr.length;}// Where the element to be moved f that // index is less than 0 when // 'moveToIndx += array size'while (moveToIndx < 0) { moveToIndx = moveToIndx + arr.length;}// If 'moveToIndx' is greater than the // size of the array then with need to // push 'undefined' in the array.if (moveToIndx >= arr.length) { let un = moveToIndx - arr.length + 1; while (un--) { arr.push(undefined); }}// Here element of 'moveEle' is removed and // pushed at 'moveToIndx' indexarr.splice(moveToIndx, 0, arr.splice(moveEle, 1));// Print the array after movingconsole.log("After move: " + arr); |
Output
Original array: C++ ,Java ,JS ,Ruby ,Python After move: C++ ,Ruby ,Java ,JS ,Python
Example 3: In this example, we will use slice(), concat(), and spread operator.
Javascript
const arr = [1, 2, 8, 4, 5];const toMove = arr[2];const newArr = [ ...arr.slice(0, 2), ...arr.slice(3), toMove];console.log(newArr); |
Output
[ 1, 2, 4, 5, 8 ]
