Try this one

var string = "abc\1234";
var newString  =string.replace('abc\','') 
gs.info(newString);

Log: 
*** Script: 1234

Please mark helpful if correct, thanks!

Hi Zack,

I'm trying to test the script in background script, but getting the following error:

Hello @Annie10,

Please try the below script.

In the script orig_string (original string) contains \\ as an escape sequence (additional / for the ServiceNow to understand that next / has no special meaning).

IndexOf function is used to identify the position of \ in the string and slice method is used to retrieve the text that is available after /.

var orig_string = "abc\\1234";
var position= orig_string.indexOf("\\")+1;
var ext_string = orig_string.slice(position);
gs.info(ext_string);

Please mark the appropriate response as correct answer and helpful, This may help other community users to follow correct solution.

Hi @Arun_S1 

My original string contains double black slash "abc\12345"

I was trying to get the number after the back slash using transform map script like this, but it did not work:

return source.u_name.toString().replace(/(\d+)/g, "");