如何通过设置一周的第一天对一周中的几天进行排序？

Question

如何分类？例如，我希望一周的第一天是星期一。由此：

周一至周二周三至周五周六

我想要这个：

星期一至星期二星期三星期五星期六至星期日

或者我希望我一周的第一天是周五

那么在输出中应该是这样的：

星期五星期六星期一星期二星期三星期四

let days = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"] //by default first day of week is 0
let firstDayOfWeek = 1 //Mon

days = days.map(m=>{
  //how i can sort this?
  return m
})

Answer 1

你可以创建一个包含2次迭代的天数组，然后使用切片从任何索引中获取7项

let days = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"]

function getSortedWeek(firstDayOfWeek, days) {
  return [...days, ...days].slice(firstDayOfWeek, firstDayOfWeek + 7)
}

console.log(getSortedWeek(1, days)) // Mon
console.log(getSortedWeek(3, days)) // Wed

Answer 2

你可以按天分类

let days = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"] //by default first day of week is 0
let firstDayOfWeek = 2 //Mon

let sorted = days.map((_, i) => days[(i+firstDayOfWeek)%7]);

console.log(sorted)

Answer 3

将firstDayOfWeek之前的天数切片，并将其添加到数组的末尾：

const orderByFirstDayOfWeek = (firstDayOfWeek, days) =>
  [...days.slice(firstDayOfWeek), ...days.slice(0, firstDayOfWeek)]

const days = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"] //by default first day of week is 0

console.log(JSON.stringify(orderByFirstDayOfWeek(1, days))) // Mon 1st
console.log(JSON.stringify(orderByFirstDayOfWeek(5, days))) // Fri 1st