CSS Selector specificity

CSSSelectorSpecificity

function sortPoints(points) {
    points.sort(function(a, b) {
        if(a[0] > b[0])
            return -1;
        if(a[0] < b[0])
            return 1;
        if(a[1] > b[1])
            return -1;
        if(a[1] < b[1])
            return 1;
        if(a[2] > b[2])
            return -1;
        if(a[2] < b[2])
            return 1;
        else 
            return 0;
    })
        
    return points;
}

function specificity(selector, element) {
    
    function is(selector, element) {
      var div = document.createElement("div"),
      matchesSelector = div.webkitMatchesSelector;
      return typeof selector == "string" ? matchesSelector.call(element, selector) : selector === element;
    }
    
    function getBiggestPoint(points) {
        var points = sortPoints(points);
        return points[0];
    }
    
    
    var splittedSelector = selector.split(',');
    var points = [];
    
    for(var i in splittedSelector) if (splittedSelector.hasOwnProperty(i)) {
        
        function numMatches(selector, regex) {
            return (selector.match(regex)||[]).length;
        }
        
        if(!is(splittedSelector[i], element)) continue;
        
        var numClasses = numMatches(splittedSelector[i], /\.[\w-_]+\b/g);
        var numIds = numMatches(splittedSelector[i], /#[\w-_]+\b/g);
        var numNamesInBraces = 0;
        var namesInBraces = splittedSelector[i].match(/\[[^\]]*\b[\w-_]+\b[^\]]*\]/g) || [];
        for (var idx = 0; idx < namesInBraces.length; ++idx) {
            numNamesInBraces += (namesInBraces[idx].match(/\b[\w-_]+\b/g)||[]).length;
        }
        var results = [0,0,0];
        results[0] = numIds;
        results[1] = numMatches(splittedSelector[i], /\[[^\]]+\]/g) + numClasses;
        results[2] = numMatches(splittedSelector[i], /\b[\w-_]+\b/g) - numIds - numClasses - numNamesInBraces;
        points.push(results);
    }
    
    return getBiggestPoint(points);
}
    
var element = document.createElement('div');
element.className = 'hello juoo';

document.write(JSON.stringify(specificity("", element)));
    
​