Swap certain element from end and start of array - JavaScript

We are required to write a JavaScript function that accepts an array of Numbers and a number, say n (n must be less than or equal to the length of array). And our function should replace the kth element from the beginning with the nth element from the end of the array.

Example

Following is the code −

const arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
const swapNth = (arr, k) => {
   const { length: l } = arr;
   let temp;
   const ind = k-1;
   temp = arr[ind];
   arr[ind] = arr[l-k];
   arr[l-k] = temp;
};
swapKth(arr, 4);
console.log(arr);
swapNth(arr, 8);
console.log(arr);

Output

This will produce the following output in console −

[
   0, 1, 2, 6, 4,
   5, 3, 7, 8, 9
]
[
   0, 1, 7, 6, 4,
   5, 3, 2, 8, 9
]

AmitDiwan

Published on 30-Sep-2020 14:15:05

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