Say I have the HTML in a string variable htmlString and I want to find the first instance of an mp3 link in the html, and store that link in a variable.
<html>
...
src="https://example.com/mp3s/2342344?id=24362456"
...
</html>
The link https://example.com/mp3s/2342344?id=24362456 will be extracted.
Note there are lots of other urls in the html, but I just want the one in this format.
How do I get this?
While it is not usually recommended to parse HTMLs using regular expressions, this expression might help you to design an expression, if you wish/have to get the first mp3 URL.
^(src=\x22(https:\/\/[a-z]+.com\/mp3s\/[0-9]+\?id=[0-9]+)\x22)[\s\S]*
I have added several boundaries to it, just to be safe, which you can simply remove it from or simplify it in the second capturing group where your desired URL is:
(https:\/\/[a-z]+.com\/mp3s\/[0-9]+\?id=[0-9]+)
The key is that to add a [\s\S]* such that it would pass everything else after capturing the first URL.
This graph shows how it would work:
repeat = 10000000;
start = Date.now();
for (var i = repeat; i >= 0; i--) {
var string = 'src=\"https://example.com/mp3s/2342344?id=24362456\" src=\"https://example.com/mp3s/08103480132984?id=0a0f8ad0f8\" src=\"https://example.com/mp3s/2342344?id=24362456\" href=\"https://example.com/mp3s/2342344?id=91847890\" src=\"https://example.com/mp3s/2342344?id0980184\"';
var regex = /^(src=\x22(https:\/\/[a-z]+.com\/mp3s\/[0-9]+\?id=[0-9]+)\x22)[\s\S]*/g;
var match = string.replace(regex, "$2");
}
end = Date.now() - start;
console.log(match + " is a match ");
console.log(end / 1000 + " is the runtime of " + repeat + " times benchmark test. ");