Split string on the first white space occurrence

Question

I didn\'t get an optimized regex that split me a String basing into the first white space occurrence:

var str=\"72 tocirah sneab\";

I need

Answer 1

Whenever I need to get a class from a list of classes or a part of a class name or id, I always use split() then either get it specifically with the array index or, most often in my case, pop() to get the last element or shift() to get the first.

This example gets the div's classes "gallery_148 ui-sortable" and returns the gallery id 148.

var galleryClass = $(this).parent().prop("class"); // = gallery_148 ui-sortable
var galleryID = galleryClass.split(" ").shift(); // = gallery_148
galleryID = galleryID.split("_").pop(); // = 148
//or
galleryID = galleryID.substring(8); // = 148 also, but less versatile 

I'm sure it could be compacted into less lines but I left it expanded for readability.