simple highlighter

highlight.js

function highlight(str){
    var colors = ['blue','rgb(9, 197, 9)','red','lightgray'];
    var reg = /(var|this|new|return|function)|([\"'].*?[\"'])|([+-]?\d+(?:\.\d+)?)|(\/\/.*|\/\*[\s\S]*?\*\/)/g;
    var res = str.replace(reg, function(match){
        var args = [].slice.call(arguments,1);
        return '<span style="color:' + colors[args.indexOf(match)] + '">' + match + '</span>';
    });
    return res;
}

// var pre = document.getElementsByTagName('pre')[0];
// pre.innerHTML = highlight(pre.innerHTML);