javascript quicky

[marc2003]

i have some urls and i simply want to extract the number in bold.

htttp://userserve-ak.last.fm/serve/_/176111/The+Verve.jpg

how can i do that?

EDIT: i've very crudely managed to come up with this....

end = urls[i].lastIndexOf("/");
start = urls[i].lastIndexOf("/",end-1) + 1;
num = urls[i].substring(start,end);

if anybody has anything tidier??

 

[Xelene]

Look at regular expressions. You'll hate me to start with.

 

[marc2003]

haha, thanks but i think i'll pass. what i have works so it'll do.

 

[dangerstat]

package regex;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class ocukReg {

	public static void main(String args[]){
		String testString = "htttp://userserve-ak.last.fm/serve/_/176111/The+Verve.jpg";

		Pattern myPattern = Pattern.compile("\\_\\/([0-9]+)");
		Matcher myMatcher = myPattern.matcher(testString);
		String Extracted ="";
		while(myMatcher.find()){
			Extracted = myMatcher.group(1);
		}
		System.out.println(Extracted);
	}
}

Ops thought this was Java rather than Javascript, not sure if it'll work in that case as I know nothing about Java script!

 

[Xelene]

package regex;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class ocukReg {

	public static void main(String args[]){
		String testString = "htttp://userserve-ak.last.fm/serve/_/176111/The+Verve.jpg";

		Pattern myPattern = Pattern.compile("\\_\\/([0-9]+)");
		Matcher myMatcher = myPattern.matcher(testString);
		String Extracted ="";
		while(myMatcher.find()){
			Extracted = myMatcher.group(1);
		}
		System.out.println(Extracted);
	}
}

Ops thought this was Java rather than Javascript, not sure if it'll work in that case as I know nothing about Java script!

There's regex objects available in JS (like just about every other language)

To the OP, you might not use them for this; but I highly recommend learning them for the future - they are really powerful.

 

[Inquisitor]

Try this:

var url = "http://userserve-ak.last.fm/serve/_/176111/The+Verve.jpg";
var matches = url.match(/^.+\/(\d+)\/.+?$/);
var number = matches[1];

This problem essentially amounts to extracting information from a string based on some simple syntactic rules, which is precisely what regular expressions are designed for. It really, really is worth learning them There's an online tool you can use to help you here:

http://www.gskinner.com/RegExr/

The expression I gave basically says "take the group of digits that occurs between the final and penultimate slashes, allowing any character to occur outside these slashes".

 

[marc2003]

thanks for the tips. i've always known they're supremely powerful. it just makes my eyes glaze over looking at them.

one day.....