remove everything before the last occurrence of a character

Question

I'm trying to perform the following action on a string :

• find the last occurrence of the character "/";
• remove everything before that character;
• return the remains of the string;

To be more explicit, let's say I have the following string :

var string = "/Roland/index.php"; // Which is a result of window.location.pathname 

Now what I need to extract out of it is everything but the actual page, something like this :

var result = "index.php" // Which is what I need to be returned 

Of course, that is just an example, because obviously I will have different pages, but the same principles apply.

I was wondering if someone could help me out with a solution for it. I tried the next actions but with no success :

var location = window.location.pathname; var result = location.substring(location.lastIndexOf["/"]); 

Answer 1

You have the right idea just replace the brackets with parentheses.

var string = "/Roland/index.php"; var result = string.substring(string.lastIndexOf("/") + 1); 

Here is an example in jsfiddle and here is an explanation of the .lastIndexOf() method on the Mozilla Developer Network.

Answer 2

Personally I'd use a regular expression:

var result = string.replace(/^.*\/(.*)$/, "$1"); 

If you're familiar with regular expressions (and you should be if not :-) then it's not as alien-looking as it is when they're unfamiliar.

The leading ^ forces this regular expression to "anchor" the match at the start of the string. The \/ matches a single / character (the \ is to keep the / from confusing the regular expression parser). Then (.*)$ matches everything else from the / to the end of the string. The initial .* will swallow up as much as it can, including / characters before the last one. The replacement text, "$1", is a special form that means "the contents of the first matched group". This regex has a group, formed by the parentheses around the last .* (in (.*)$). That's going to be all the stuff after the last /, so the overall result is that the whole string is replaced by just that stuff. (If the pattern doesn't match because there aren't any / characters, nothing will happen.)