数组去重

arrCombine: function(arr){
        var equalsByURL = function (sobj, tobj) {
            var flag = 'url' in sobj ? sobj['url'] === tobj['url'] : false;
            return flag;
        }
        var _targetArr = [];
        var tarObj = null;
        var curObj = null;
        var cur = 0;
        var length = arr.length;
        for(var i = 0; i < length; i ++ ){
            curObj = arr[i];
            if(!curObj) continue;
            for(var j = i + 1; j < length; j ++) {
                tarObj = arr[j];
                if(!tarObj) continue;
                var flag = equalsByURL(curObj, tarObj);
                if(flag) {
                    if(curObj.str)
                        curObj.str += tarObj.str;
                    //curObj.num += '_' + tarObj.num;
                    var s = curObj.str.split('\n');
                    s.pop();
                    s.sort(function(x,y){
                        x = parseInt(x);
                        y = parseInt(y)
                        return x - y;
                    });
                    curObj.str = s.join('\n')+'\n';
                    arr[j] = undefined;
                }
            }
            _targetArr.push(curObj);
            arr[i] = undefined;
        }
        return _targetArr;
 }