Return First Character of each word in a string

I would suggest you to use RegExp, Here's an Example

var myStr = "John P White";
var matches = myStr.match(/\b(\w)/g);
console.log(matches.join(''));

\b assert position at a word boundary (^\w|\w$|\W\w|\w\W)

1st Capturing Group (\w)

\w matches any word character (equal to [a-zA-Z0-9_])

Global pattern flags

g modifier: global. All matches (don't return after first match)

For better explanation visit here