Javascript Regex Replace Exact character

I have this code

htmlString= htmlString.replace( new RegExp( "WW(.+?)WW", "gim" ),
    "<span style='color:red;border-bottom:1px dashed red;'>$1</span>" );

This seems to work however it is replacing the www's in url's. What I have is WW somestring WW I clip out the text between WW and replace it. However, I can't seem to only get the exact char sequence. I tried {WW} ^WW [^WW] with the end [$WW] and variat开发者_如何学Pythonions. Also tried \bWW string \bWW and no match.

Any help would be great, thanks.

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Assuming that there is something else than alphanumeric characters after the starting WW and before the ending WW (whitespace, for example), then you could do this:

htmlString = htmlString.replace(/\bWW\b\s*(.+?)\s*\bWW\b/g, 
    "<span style='color:red;border-bottom:1px dashed red;'>$1</span>" );

Using a regex object instead of a string literal makes it easier to read. If you had used \b in a string literal it would have meant "backspace" - you need to escape backslashes in a string literal, so the above regex would become "\\bWW\\b\\s*(.+?)\\s*\\bWW\\b".

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If the text you're looking to replace is always uppercase and the www you don't want to replace is always lowercase, then you can just replace the "gim" with "gm": the i indicates ignore case. The m in "gim" has no meaning in a RegExp so you can reduce to "g".