I didn't see the replies until your comment Andrew, but now that I come back to it I don't see why it would break for long words. I think I saw indexOf and thought charAt or some such thing. I don't know, this looks like it works to me.

Also I don't get the FUD about using regex, they're not slow in general. Some regex can be slow, but one that looks for a single digit is as fast as indexOf.

@prohairesis Give it a check, the function indeed breaks for really long words.

That is not true. He is not looping through each letter intentionally. The test case you provide, "longlonglongword2 hello1", would still pass. He does not need to loop through each letter, he is using .indexOf on the entire word to find the index from the outer loop contained within the ENTIRE word. If not, continue looping until it finds it. Once it finds it, push it to result.

In this case it not only copies the array so it isn't modified (a best practice) but also handles when n is less than 3. Without it he'd return the whole signature.

It also doesn't "iterate n times".

This solutions mutates the input and creates a global variable.

If you want to write a golfy solution, you need to make it look like one ;-)

Too much white space, you have unnecessary indentation!