Javascript, Regex, Reverse match

Question

I try to get the following using js regex:

string</span>string</span>string</span>theStrngIWant

In one sentence i try to get any characters including new lines after the last </span>

I try this pattern /<\\/span>((.|\\n)*)/i , I know the pattern won't work i just wanted to show what i want to capture:

So after the last </span> i want to capture anything included in the . token and because its not include new lines i added \\n , I think its ok to use greedy without ? because its the end of the string anyway, Also just to note i did try negative lookahead.

If any one know any regex for this case i will be very thankful.

Answer 1

Don't parse HTML using Regex

First, you are asking for trouble if you decide to parse HTML using regex for any production/important code.

That said, for non-critial rough editing purposes, HamZa's pattern works just fine. Here is a slightly more complex, (but more efficient) pattern in the form of a tested JavaScript function:

function processText(text) {
/*  # Capture in $1, everything following last SPAN element.
    <\/span\s*>        # Last SPAN close tag.
    (                  # $1: Everything after last SPAN.
      [^<]*            # Zero or more non start-of-tag chars.
      (?:              # Zero or more non-SPAN tags.
        <              # Allow start of any HTML tag, but
        (?!\/?span\b)  # only if not start a SPAN tag.
        [^<]*          # Zero or more non start-of-tag chars.
      )*               # End zero or more non-SPAN tags.
    )                  # End $1: Everything after last SPAN.
    $                  # Anchor to end of string.
*/
    var re = /<\/span\s*>([^<]*(?:<(?!\/?span\b)[^<]*)*)$/i;
    var m = text.match(re);
    return (m) ? m[1] : '';
}

The regex is also presented (as a multi-line comment) in free-spacing mode with indentation and comments describing each bite-size regex chunk.

Learning Regex

For more info on how to write a good regex, I recommend reading the tuorial at: regular-expressions.info/ . If you would like to become a regex guru, then you would be well served by reading: Mastering Regular Expressions (3rd Edition)