如何获取字符串的所有字符的子字符串除了最后两位数字？ （例如：031p2 >>获得031）

Question

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

How can I get the 01 without the last two chars? The trick is that if i do it like (0,2) it does get the first 2 numbers but this id will also be a three digit number... so I just need to get rid of the last two digits. This works with substr in PHP, how come (0,-2) doesn't work with javascript? More importantly how can i make this work?

Answer 1

您正在寻找slice() （另见MDC ）

id.slice(0, -2)

Answer 2

尝试id.substring(0, id.length - 2);

Answer 3

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

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

Answer 4

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.