javascript - JS Date 不是以前导 0 开头 - 可能重复的问题

Question

我正在尝试从这种格式转换我的数组

ka_layers2 = ["1-05-2019","2-05-2019" ........,"15-05-2019",.."27-05-2019"]

像这样，

"01-05-2019","02-05-2019"

这是我的代码

for(i = 0; i < ka_layers2.length; i++){
  var months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];
  var d = new Date(ka_layers2[i]);
  var day = console.log("0"+d.getDate()).slice(-2);
  console.log(day);
  ka_layers2arr.push(day + '-' + months[d.getUTCMonth()] + '-' + d.getUTCFullYear());
}

但这给我带来了一个问题，“无法读取未定义的属性‘slice’”

我正在尝试这个问题中提到的答案。 Javascript add leading zeroes to date

Answer 1

使用正则表达式

/\b(\d)\b/g demo

let dates = ["1-05-2019", "2-05-2019", "15-05-2019", "27-05-2019"]

let result = dates.map(date => date.replace(/\b(\d)\b/g, '0$1'))

console.log(result)