Question

How can I sub a string according the 3th character
for example: I have the string “aaa://Google/gmail”
and I want to get a new string
till the 3th “/”, new string = “aaa://Google/”

Answer 1

Something like this should do

var str = "aaa://Google/gmail",
    matches = str.split('/');
str = matches.slice(0, 3).join('/') + ( matches.length > 3 ? '/' : '' )

If you don’t care about the trailing slash, it’s simpler:

 "aaa://Google/gmail".split('/').slice(0,3).join('/')