如何删除PHP中的某些尾随字符？

I'm trying to make a LaTeX parser in PHP, and I want to remove certain trailing new lines (\\ signs).

But the problem is, I only want to remove the new line (the double backslash) if it's before everything else.

Like, I want to remove the first \\ in the following example:

\\3+6=9

But not this \\:

3+\\6=9

How can I do this with PHP?

use trim

$arr = trim('your_string','\\');

working example http://codepad.viper-7.com/OaYxWG

Use trim in php

i.e.,

trim("string","\\");

You can do the following

$a = "\\aaaaa";

if (substr($a, 0, 1) === '\\') { 
    echo trim($a,'\\');     
 }

It will echo out "aaaaa". Hope this helps