The String startsWith() method

Check if a string starts with the value of the string passed as parameter.

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