Question

我正在研究制作日历的程序。以YYYY / MM / DD格式记录数字时，应发生以下情况：

console.log(talkingCalendar("2004/11/01"));    =>  November 1st, 2004
console.log(talkingCalendar("2007/11/11"));    =>  November 11th, 2011
console.log(talkingCalendar("1987/08/24"));    =>  August 24th, 1987

这是我正在研究的：

function tensFn(day) {
  var output = 0;
  if (day.length > 1) {
    output = day[0];
  }

    return output;
  }

function getOrdinal(day) {
  var ones = day.toString().split('').pop();
   ones = parseInt(ones);
   var tens = parseInt(tensFn(day), 10);
   var ordinate = '';
   if (tens == 0  || tens == 2) {
     switch (ones) {
     case 1:
       ordinate = 'st';
       break;
     case 2:
       ordinate = 'nd';
       break;
     case 3:
       ordinate = 'rd';
       break;
     case 4: case 5: case 6: case 7: case 8: case 9:
      ordinate = 'th';
      break;
  }

  }


  if (tens == 1) {
    switch (ones) {
    case 1: case 2: case 3: case 4: case 5: case 6: case 7: case 8: case 9:
     ordinate = 'th';
  }

  }

  return ordinate;
}

这是我没有完全掌握的部分：

function getOrdinal(day) {
  var ones = day.toString().split('').pop();
   ones = parseInt(ones);
   var tens = parseInt(tensFn(day), 10);
   var ordinate = '';

作者对var的处理方式是什么，为什么将其转换为字符串，先拆分然后在解析前弹出？

Answer 1

从我所见，它用来分隔日子。示例编号27分为20和7。

 function getOrdinal(day) {                         Example day = 27
    var ones = day.toString().split('').pop();      convert 27 to '27', split on chars ['2','7'] and pop '7'
    ones = parseInt(ones);                          convert to integer the result from above 7 
    var tens = parseInt(tensFn(day), 10);           get the first number when days length is greater than 1. In this case returns 2 
}

我认为一种更好的方法是：

function getOrdinal(day){           Example day = 27
    var ones = day % 10             get 27 mod 10 = 7
    var tens = day / 10 |0          get difference of days / ten, then floor it. Result is 2
    var ordinate = '';
    ...

function getOrdinal(day){		    
	var ones = day % 10			     
	var tens = day / 10 |0	
	return [ones, tens]
}

console.log(getOrdinal(27))

了解制作日历的程序吗？

1 个答案: