javascript - After converting the string date into a general time format, it is found that numbers less than 10 will not automatically add 0 in front, as follows

Question

Instead of using string concatenation (less than 10, manually add 0 in front), is there any other way?

習慣沉默 · Answer

Usually you don’t just write a JS paragraph to judge. If it’s less than 10, add a 0 in front

扔个三星炸死你 · Answer

function formatTime(date) {
  var year = date.getFullYear()
  var month = date.getMonth() + 1
  var day = date.getDate()

  var hour = date.getHours()
  var minute = date.getMinutes()
  var second = date.getSeconds()
  return [year, month, day].map(formatNumber).join('-') + ' ' + [hour, minute, second].map(formatNumber).join(':')
}
function formatNumber(n) {
  n = n.toString()
  return n[1] ? n : '0' + n
}