how to get the next item from an javascript array?-CodePudding

So, i have built and array of all the month and i am to get the current month from it by using the getDate function but i wanna scroll through it

const month = ["Januray", "Feburary", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]

let d = new Date();
let showMonth = month[d.getMonth()]
monthEl.textContent = showMonth

how to i get the next month when i click on a element with onclick="next()" i have read other various solutions but those consists of complex arrays that i am unable to comprehend due to myself being new programming

CodePudding user response：

You can get the next month by keeping track of the index of the array. Increment the index on a call to next() and pull out the next month from the array using that incremented index month[nextIndex];

The only gotcha is if the index grows beyond the length of the array, which will result in you getting back undefined instead of the month- so we have to check for this. if (nextIndex > month.length - 1) then set the index back to the beginning, 0 and now you have something that will loop through the array.

also you have a small typo in Janurary and Feburary.

const monthEl = document.getElementById("monthEl");
let monthIndex = 0;
const month = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]

let d = new Date();
monthIndex = d.getMonth();
let showMonth = month[monthIndex]
monthEl.textContent = showMonth;

function next() {
  let nextIndex =   monthIndex;
  if (nextIndex > month.length - 1) {
    nextIndex = 0;
    monthIndex = 0;
  }

  let nextMonth = month[nextIndex];
  monthEl.textContent = nextMonth;

}

<div id="monthEl"></div>
<button onClick="next()">next</button>

CodePudding user response：

This function can deal with the scroll I hope it helps you Once it reach the last item of the array will show again the first and so on in a loop.

const month = ["Januray", "Feburary", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]

function monthsCal(){
  let refPosition  = -1;
  return {
    next(){
      const pos = (  position)%month.length
      return month[pos]
    }
  }
}

const s = monthsCal()
console.log(s.next()) // Januray
console.log(s.next()) // Feburary
console.log(s.next()) // March
// etc...