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Remove empty tags using RegEx

I want to delete empty tags such as <label></label>, <font> </font> so that:

<label></label><form></form>
<p>This is <span style="color: red;">red</span> 
<i>italic</i>
</p>

will be cleaned as:

<p>This is <span style="color: red;">red</span> 
<i>italic</i>
</p>

I have this RegEx in javascript, but it deletes the the empty tags but it also delete this: "<i>italic</i></p>"

str=str.replace(/<[S]+></[S]+>/gim, "");

What I am missing?

Answer

You have “not spaces” as your character class, which means “<i>italic</i></p>” will match. The first half of your regex will match “<(i>italic</i)>” and the second half “</(p)>“. (I’ve used brackets to show what each [S]+ matches.)

Change this:

/<[S]+></[S]+>/

To this:

/<[^/>][^>]*></[^>]+>/

Overall you should really be using a proper HTML processor, but if you’re munging HTML soup this should suffice 🙂