json數組按照日期先後排序

var allMyApp = [
                {"startDate": "2018-07-07 12:30:00",'name':'aa'},
                {"startDate": "2018-07-09 12:30:00",'name':'bb'},
                {"startDate": "2018-07-05 12:30:00",'name':'cc'},
                {"startDate": "2018-07-01 12:30:00",'name':'dd'}
            ];
            var newArr = [];
            for(var p = 0; p < allMyApp.length; p++){
                  newStartDate = (allMyApp[p].startDate).replace(new RegExp("-", "gm"), "/");
                startHaoMiao = (new Date(newStartDate)).getTime(); //得到毫秒數
                newArr.push(allMyApp[p])
                newArr[p].timeStartApp = startHaoMiao;
            }
            console.log(newArr);
            var arr = newArr.sort(sortDate);
　　　　　　　　//arr就是最終的排序後的數組
            console.log(arr);
            
            function sortDate(a,b){
                return a.timeStartApp-b.timeStartApp
            }