JavaScript Get real length of a string (without entities)

Question

I need to determine the length of string which may contain html-entities.

For example \"&darr ;\" (↓) would return length 6, which is correct, but I want these

Answer 1

You could for most purposes assume that an ampersand followed by letters, or a possible '#' and numbers, followed by a semicolon, is one character.

var strlen=string.replace(/&#?[a-zA-Z0-9]+;/g,' ').length;