http://www.w3schools.com/jsref/jsref_split.asp
var str="How are you doing today?";
var n=str.split(" ");
Result :
How,are,you,doing,today?
In your case :
var url="http://safebooru.org//images/813/a8b349b60d0c448eb86cfb99e24318ad6d48b7df.jpg?818629";
var array = url.split("?");
var myNewUrl = array[0];
1
solved How to strip out string after question mark?