Open In App

How to check a string is entirely made up of the same substring in JavaScript ?

Improve
Improve
Like Article
Like
Save
Share
Report

In this article, we are given a string and the task is to determine whether the string is made up of the same substrings or not.

Approach: Using Regular Expression with test() method

  • Initialize a string to the variable.
  • Use the test() method to test a pattern in a string.
  • The test() method returns true if the match is found, otherwise, it returns false.

Example 1: This example checks for string geeksgeeksgeeks which is made up of the same substring, so it returns True. 

Javascript




// Input string
let str = "geeksgeeksgeeks";
 
// Function to check if string is made of same substring
function check(str) {
    return /^(.+)\1+$/.test(str)
}
 
let ans = "String is not made up of same substrings";
 
if (check(str)) {
    ans = "String is made up of same substrings";
}
 
// Display output
console.log(ans);


Output

String is made up of same substrings

Example 2: This example checks for string geeksgeekgeeks which is not made up of the same substrings so it returns False. 

Javascript




// Input string
let str = "geeksgeekgeeks";
 
// Function to check if string is made of same substring
function check(str) {
    return /^(.+)\1+$/.test(str)
}
 
let ans = "String is not made up of same substrings";
 
if (check(str)) {
    ans = "String is made up of same substrings";
}
 
// Display output
console.log(ans);


Output

String is not made up of same substrings



Last Updated : 20 Jul, 2023
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads