Jsは現在の日付を取得し、現在の日付を計算します.今年の何日目ですか?

var dateArr = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
var date = new Date();
var day = date.getDate();
var month = date.getMonth(); //getMonth()  0  
var year = date.getFullYear();
var result = 0;
for ( var i = 0; i < month; i++) {
	result += dateArr[i];
}
result += day;
//      
if (month > 1 && (year % 4 == 0 && year % 100 != 0) || year % 400 == 0) {
	result += 1;
}
alert("   " + year + " " + (month + 1) + " " + day + " ,     " + result+ " ");