Here are samples:

• example 1: string1<span id="header">5655811</span>string2
• example 2: string3<span id="header">51481</span>string4
• example 3: string5<span id="header">854211</span>string6

How can I get the number between <span id="header"> and </span> with JavaScript regex?

Here are samples:

• example 1: string1<span id="header">5655811</span>string2
• example 2: string3<span id="header">51481</span>string4
• example 3: string5<span id="header">854211</span>string6

How can I get the number between <span id="header"> and </span> with JavaScript regex?

• javascript
• regex
• html-parsing

• Have you tried anything yet – aaronman Commented Aug 29, 2013 at 16:47
• Aside: Ids should be unique. Use classes instead. – Derek Commented Aug 29, 2013 at 16:51
• You can't assume from his answer that he's not using IDs uniquely: he's just presenting three examples, they could be on different pages, or different loads of the same page, and the header ID could still be unique. Not that it's ever a bad thing to remind people that IDs should be unique. – Ethan Brown Commented Aug 29, 2013 at 16:54

1 Answer 1

It depends on how safe you want to be. If you're sure that all of your input looks exactly like you have in your message, you can use:

var n = Number( input.match( /<span id="header">(\d+)<\/span>/ )[1] );

A slightly safer version would be:

var n;
var match = input.match( /<span id="header">\s*(\d+)\s*<\/span>/ );
if( match ) {
    n = Number( match[1] );
} else {
    // do error handling here
}