Finding Substring and Repeating string in Javascript

There are several methods you can use to find substrings in JavaScript:

indexOf(): Returns the index of the first occurrence of the specified substring within a string, or -1 if the substring is not found.

let str = "Hello world";
let substr = "world";
let index = str.indexOf(substr);

console.log(index); // Output: 6

lastIndexOf(): Returns the index of the last occurrence of the specified substring within a string, or -1 if the substring is not found.

let str = "Hello world";
let substr = "l";
let index = str.lastIndexOf(substr);

console.log(index); // Output: 9

search(): Searches for a specified substring within a string and returns the position of the match, or -1 if the substring is not found.

let str = "Hello world";
let substr = "world";
let index = str.search(substr);

console.log(index); // Output: 6

includes(): Determines whether a string contains the specified substring and returns true or false.

let str = "Hello world";
let substr = "world";
let found = str.includes(substr);

console.log(found); // Output: true

startsWith(): Determines whether a string begins with the specified substring and returns true or false.

let str = "Hello world";
let substr = "Hello";
let found = str.startsWith(substr);

console.log(found); // Output: true

endsWith(): Determines whether a string ends with the specified substring and returns true or false.

let str = "Hello world";
let substr = "world";
let found = str.endsWith(substr);

console.log(found); // Output: true

Note that all these methods are case-sensitive. If you want to perform a case-insensitive search, you can convert both the string and the substring to lowercase or uppercase before performing the search.

Repeating string

output

String Padding