Array of string that looks like a date-CodePudding

If I have an array like: let array = ["Friday, 11 February","Tuesday, 10 February","Friday, 04 March", "Thursday, 17 February", "Today", "Monday, 9 February"];. What I try to do is to find the closest date to today or the smaller and I don't want to take "Today". Until now I tried:

let array = ["Friday, 11 February","Tuesday, 10 February","Friday, 04 March",  "Thursday, 17 February", "Today", "Monday, 9 February"];
array = array.map(el => el.split(", ").slice(1).join()).filter(el =>el)
let months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
let closest = "";

for(let i = 0; i < array.length; i  ){
    for(let j = 1; j < array.length; j  ){
    let numberOne = array[i].match(/\d /)[0];
    let monthOne = array[i].match(/\b[a-zA-Z] \b/g)[0];
    let numberTwo = array[j].match(/\d /)[0];
    let monthTwo = array[j].match(/\b[a-zA-Z] \b/g)[0];
    if( (numberOne) <  (numberTwo) && months.indexOf(monthOne) <= months.indexOf(monthTwo)){
      closest = array[i]
    }
   
  }
}
console.log(closest)

Everything is ok but I want to know if I can transform in a Date and sort by date. Anyone have a solution to this or a cleaner way to find the closest date? The array is dynamic and until now I didn't find any date which is before today and to take that one. Thank you!

CodePudding user response：

First of all, here are one issue: year is not defined, so let's clarify we mean current year by transforming all dates to actual Date:

const now = new Date();
array.map(el => new Date(`${el} ${now.getFullYear()}`);

Then we can calculate differences from now (in milliseconds):

array.map(el => new Date(`${el} ${now.getFullYear()}`) - now.getTime());

Let's wrap them into Math.abs to easely find which one in smallest using Math.min():

const offsets = array.map(el => Math.abs(new Date(`${el} ${now.getFullYear()}`) - now.getTime()));
const closestIndex = offsets.findIndex(el => el === Math.min(...offsets));

closestIndex - index of date with smallest offset which means "closest to now".

Full code (excluding "Today" from the beginning):

const array = ["Friday, 11 February", "Tuesday, 10 February", "Friday, 04 March",  "Thursday, 17 February", "Today", "Monday, 9 February"].filter(el => el !== 'Today');

const now = new Date();

const offsets = array.map(el => Math.abs(new Date(`${el} ${now.getFullYear()}`) - now.getTime()));

const closestIndex = offsets.findIndex(el => el === Math.min(...offsets));

console.log(array[closestIndex]);

CodePudding user response：

I thought about the possibility that some dates could be the next year. The best example the end of December and the begining of January and I write the next code, which I hope can help someone

let array = [
  "Tuesday, 03 January",
  "Thursday, 05 January",
  "Thursday, 29 December",
  "Monday, 02 January",
  "Friday, 30 December"
];
let now = new Date();
var datesArray = array.map((el) => el   " "   now.getFullYear());
datesArray = datesArray.map((el) => new Date(el));
datesArray = datesArray.map(el => {
  if (el.getTime() < now.getTime()) {
    return el = el.setFullYear(el.getFullYear()   1)
  }else{
    return el = el.setFullYear(el.getFullYear())
  }
})
const closestIndex = datesArray.findIndex(el => el === Math.min(...datesArray));
console.log(array[closestIndex])