How to return all except last 2 characters of a string?

id = '01d0';
document.write('<br/>'+id.substr(0,-2));

How can I take a string like '01d0开发者_JS百科and get the01` (all except the last two chars)?

In PHP I would use substr(0,-2) but this doesn't seem to work in JavaScript.

How can I make this work?

You are looking for slice() (also see MDC)

id.slice(0, -2)

Try id.substring(0, id.length - 2);

var str = "031p2";
str.substring(0, str.length-2);

See : http://jsfiddle.net/GcxFF/

Something like:

id.substr(0, id.length - 2)

The first parameter of substr is the starting index. The second parameter is how many characters to take.