基于当月的 12 个月动态数组

Question

我正在尝试基于当前月份构建一个 12 个月的数组，因此当前月份是三月我的数组应该如下所示：

const months =[“March”, “February”, “January”, “December”, “November”, “October”] etc, all the way to 12 previous months

Answer 1

Well, create an array with the months and adjust it based on the current month

 const months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'], month = (new Date()).getMonth(), previous = months.splice(0, month); // if you have to use this in a front-end app, you might want to use .concat(...) instead of the spread operator const output = [...previous.reverse(), ...months.reverse()] console.log(output)

Answer 2

 const months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sept', 'Oct', 'Nov', 'Dec']; let curMonth = 'Mar', ctr = 0, ref = months.indexOf(curMonth), sorted = []; while (ctr <= 11) { let n = ref - ctr n = n >= 0 ? n : 11 + n; let m = months[n] sorted.push(m) ctr++; } console.log(sorted)

Answer 3

const months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
const currentMonth = "March";

// First find current month index
const currentMonthIndex = months.findIndex((item) => currentMonth === item)

// Then reorder the array
const orderedMonths = months.slice(currentMonthIndex).concat(months.slice(0, currentMonthIndex));
console.log('orderedMonths', orderedMonths);

Here is a working fiddle https://jsfiddle.net/uot8Lfdr/2/

Answer 4

Using the array prototype methods, concat, splice, and reverse, you can manipulate a list of months to produce the array you want.

You can get the current month as a number using new Date().getMonth()

 const months = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]; const offsetReverseMonths = months.concat(...months.splice(0, new Date().getMonth())).reverse(); console.log(offsetReverseMonths);

Answer 5

Dynamically without an initial array using Date#toLocaleString() to retrieve month names.

This gives you access to localization automatically by accepting a locale as a parameter. It should be noted that this will use the local system timezone, you'll need to adjust if you want UTC.

 function getPriorTwelveMonths({ date = new Date, locale = 'default' } = {}) { const monthName = (date) => date.toLocaleString(locale, { month: 'long' }); let month = date.getMonth(), result = []; for (let i = 0; i < 12; i++) { date.setMonth(((month - i) + 12) % 12); result.push(monthName(date)); } return result; } const defaults = getPriorTwelveMonths(), // pass a locale korean = getPriorTwelveMonths({ locale: 'ko-KR' }), // or a date and locale frenchDec1995 = getPriorTwelveMonths({ date: new Date('1995-12-17T03:24:00'), locale: 'fr' }); console.log(`[${defaults.join(',')}]`); console.log(`[${korean.join(',')}]`); console.log(`[${frenchDec1995.join(',')}]`);

 .as-console-wrapper { max-height: 100% !important; top: 0; }

Answer 6

If you have control over how the months are defined, you could define them backwards to start, and avoid using reverse() , or other loops.

const months = ["December", "November", "October", "September", "August", "July", "June", "May", "April", "March", "February", "January"];
const monthSpot = 12 - new Date().getMonth() - 1;
const result = [...months.splice(monthSpot, 12), ...months];
console.log(result);