How to do a regular expression to remove only the hyphen without removing the hyphenated arrow

You can use negative lookahead "(?!) , deny a coming pattern the front of another pattern. Example in php:

preg_replace('/-(?!>)/', '', '00000-001->22222-222');

Or in javascript:

var result = '00000-001->22222-222'.replace(/-(?!>)/g, '');
document.write(result);

The /-(?!>)/ pattern means " - that is not directly followed by > " and will return "00000001->22222222" .

You can do this:

var str = '00000-001->22222-222';
var limpa = str.replace(/\-/g, function(match, pos) {
    return str.slice(pos + 1, pos + 2).match(/\d/) ? '' : '-';
});
console.log(limpa); // dá 00000001->22222222

jsFiddle: link

or as BrunoRB suggested :

var str = '00000-001->22222-222';
var limpa = str.replace(/\-([^>])/g, '$1');
console.log(limpa); // dá 00000001->22222222

jsFiddle: link