ES6, introduced in 2015, added the startsWith() method to the String object prototype.

This is the way to perform this check in modern JavaScript

This means you can call startsWith() on any string, provide a substring, and check if the result returns true or false:

'testing'.startsWith('test') //true
'going on testing'.startsWith('test') //false

This method accepts a second parameter, which lets you specify at which character you want to start checking:

'testing'.startsWith('test', 2) //false
'going on testing'.startsWith('test', 9) //true

More js tutorials: