In order to reverse the string in its place, We’re going to use a number of methods and the most preferred ones. There are following methods to do so.
Methods to Reverse a String in Place:
- Using JavaScript split() method
- Using Array reverse() method
- Using join() method
- Using substr() method
Method 1: Using the JavaScript split() method
JavaScript String split() Method is used to split the given string into an array of strings by separating it into substrings using a specified separator provided in the argument.
Example: This example reverses the string by first splitting it with (“”) separator and then reversing it and finally joining it with (“”) separator.
Javascript
let str = "This is GeeksForGeeks";console.log("Input string is : " + str);function gfg_Run() { console.log( "Reverse String" + str.split("").reverse().join("") );}gfg_Run(); |
Input string is : This is GeeksForGeeks Reverse StringskeeGroFskeeG si sihT
Method 2: Using the Array reverse() method
JavaScript Array.reverse() Method is used for the in-place reversal of the array. The first element of the array becomes the last element and vice versa.
Example: This example uses the concept of the merge sort algorithm.
Javascript
// Input stinglet str = "This is GeeksForGeeks";console.log("Input string is : " + str);// Function to reverse stringfunction reverse(s) { if (s.length < 2) return s; let hIndex = Math.ceil(s.length / 2); return ( reverse(s.substr(hIndex)) + reverse(s.substr(0, hIndex)) );}// Function to display outputfunction gfg_Run() { console.log(reverse(str));}// Function callgfg_Run(); |
Input string is : This is GeeksForGeeks skeeGroFskeeG si sihT
Method 3: Using the Array join() method
The JavaScript Array join() Method is used to join the elements of an array into a string. The elements of the string will be separated by a specified separator and its default value is a comma(, ).
Example: This example takes a variable and appends the result from the end of the string.
Javascript
// Input stinglet str = "A Computer Science Portal";console.log("Input string is : " + str);// Function to reverse stringfunction reverse(s) { // Variable to store reverse let o = ""; for (let i = s.length - 1; i >= 0; o += s[i--]) {} return o;}// Function to display outputfunction gfg_Run() { console.log(reverse(str));}// Function callgfg_Run(); |
Input string is : A Computer Science Portal latroP ecneicS retupmoC A
Method 4: Using substr() method
JavaScript str.substr() method returns the specified number of characters from the specified index from the given string. It basically extracts a part of the original string.
Example: This example uses str.substr() method to reverse a string.
Javascript
// Input stinglet str = "This is GeeksForGeeks";console.log("Input string is : " + str);// Function to reverse stringfunction reverse(s) { if (s.length < 2) return s; let hIndex = Math.ceil(s.length / 2); return ( reverse(s.substr(hIndex)) + reverse(s.substr(0, hIndex)) );}// Function to display outputfunction gfg_Run() { console.log(reverse(str));}// Function callgfg_Run(); |
Input string is : This is GeeksForGeeks skeeGroFskeeG si sihT