Split string and keep the separator

Question

I\'m writing a chrome extension, and I need to split a string that contains only text and img tags, so that every element of the array is either letter or img tag. For example,

Answer 1

The reason you get empty elements is the same why you get inyour results. When you use capturing parentheses in a split pattern, the result will contain the captures in the places where the delimiters were found. Since you have (|), you match (and capture) an empty string if the second alternative is used. Unfortunately, ()| alone doesn't help, because you'll still get undefined instead of empty strings. However, you can easily filter those out:

str.split(/(]*>)|/).filter(function(el) { return el !== undefined; });

This will still get you empty elements at the beginning and the end of the string as well as between adjacent tags, though. So splitting would result in

["", "", "", "", ""]

If you don't want that, the filter function becomes even simpler:

str.split(/(]*>)|/).filter(function(el) { return el; });