I want to extract the first valid URL in a string, which can be anywhere between characters and whitespace
I have tried with the following
...
urlReg
Your regex
is incorrect.
Correct regex for extracting URl : /(https?:\/\/[^ ]*)/
Check out this fiddle.
Here is the snippet.
var urlRegex = /(https?:\/\/[^ ]*)/;
var input = "https://medium.com/aspen-ideas/there-s-no-blueprint-26f6a2fbb99c random stuff sd";
var url = input.match(urlRegex)[1];
alert(url);
That's because the match result holds the whole string first that matches, then the groups. I guess you want the group, so you can do this:
url[1]
Here's a fiddle: http://jsfiddle.net/jgt8u6pc/1/
Live Demo with regex explanation on left side.
Regex explanation
var regex = /^(https?:\/\/[^/]+(\/[\w-]+)+)/;
var str = 'https://medium.com/aspen-ideas/there-s-no-blueprint-26f6a2fbb99c random stuff sd';
var url = str.match(regex)[0];
document.write(url);