Best way to replace middle element of array (dynamic) in Javascript-CodePudding

I am still pretty new to programing and have been working on challenges. One of them is creating a function that will:

-> Change the middle value in an odd array to a string "Hi" -> Return an even array as it is (no changes)

I have managed to find the middle element in the array with no problem (also setting up the condition for even arrays).

But I am struggling to figure out how to actually replace the element with a string and return the array.

For example [1, 2, 3, 4, 5] -> [1, 2, 'hi", 4, 5]

If anyone can point me in the right direction I would be very grateful. Thank you all for your help

function hiInTheMiddle(arry) {
  if(arry.length % 2 === 0) {
    return arry
  }
  let middle = arry[Math.floor((arry.length - 1) / 2)];
}

CodePudding user response：

You can simply change the middle element with arr[middle] = 'Hi'

So the code you need should be something like this:

let evenArr = [1, 2, 3, 4];
let oddArr = [1, 2, 3, 4, 5, 6, 7];

function hiInTheMiddle(arr) {
  if (arr.length % 2 === 0) {
    return arr;
  }
  
  arr[arr.length / 2 - 0.5] = 'Hi';
  return arr;
}

console.log(hiInTheMiddle(evenArr)); console.log(hiInTheMiddle(oddArr));

CodePudding user response：

You can simply achieve this requirement by just finding the index of middle element by using String.indexOf() method and then assign the hi string to that index.

Live Demo :

function hiInTheMiddle(arry) {
  if(arry.length % 2 === 0) {
    return arry;
  }
  let middle = arry[Math.floor((arry.length - 1) / 2)];
  arry[arry.indexOf(middle)] = 'hi';
  return arry;
}

const res = hiInTheMiddle([1, 2, 3, 4, 5]);

console.log(res);