How to implement a regular expression?

Question

JavaScript

I want to make my own highlighting and everything is going fine, but these regular seasons are difficult for me :) Help me make the highlighting right.

var find = new Array(
        /(function|var|if|else|return|\&\&|\?|\:|===|==|=|\<|\>|\+\+|\-\-|\*|\%|\$|\@|\!)/g,
        /(setTimeout|appendTo)/g,
        /\/\/(.+)/g
        );

    var replacing = function(syntax,i){
    	var arr = new Array(
          "<span class=\""+ syntax +" ff\">$1</span>",
          "<span class=\""+ syntax +" fn\">$1</span>",
          "<span class=\""+ syntax +" cc\">//$1</span>"
          );
    	return arr[i];
    }

It highlights like this:

And it is necessary that it highlights not only, for example , $ , but the entire variable.
Who can share regular expressions, but not plugins. I've already looked and it's better to make my own than to correct someone else's code.

Answer 1

And I thought that I don’t like ready-made solutions :D

\$[a-z]+[^ ] // вместо a-z укажи все допустимые символы для переменных

Answer 2

Try

var find = new Array(
        /(function|var|if|else|return|\&\&|\?|\:|===|==|=|\<|\>|\+\+|\-\-|\*|\%|\$\w*|\@|\!)/g,
        /(setTimeout|appendTo)/g,
        /\/\/(.+)/g
        );