How to String.match() distinct it ${SOME_TEXT} using Regex

Question

I need this string:

var x = \'Hi ${name}! How are you? ${name}, you are old! ${name} share with ${other} how do u ${feel}!\'

I need to know

Answer 1

I find this solution at #regex IRC Channel by farn user:

x.match(/\$\{([^\}]+)\}(?![\S\s]*\$\{\1\})/g);

output:

['${name}',
 '${other}',
 '${feel}']

and

x.match(/\$\{([^\}]+)\}(?![\S\s]*\$\{\1\})/g).length;

output:

3

:)