Looking to swap out the final value in a JavaScript array?

Question

Looking to swap out the final value in a JavaScript array?

My task involves manipulating arrays. I start with an array of numbers called newArr. The length of this array is used to create another array filled with zeros, which I named zeroArr.

const newArr = [1,3,5,8,9,3,7,13]
const zeroArr = Array.from(Array(newArr.length), () => 0);
console.log(zeroArr) // [0,0,0,0,0,0,0,0]

Now, the goal is to change the value at the last index of zeroArr from 0 to 10, so it should end up like this:

const result = [0,0,0,0,0,0,0,10]

How can I achieve this modification?

javascript arrays

Answer 1

Answer №1

To update the final element in an array, you can use this method:

result[result.length-1] = 10;

Check out this Stack Snippets demonstration

const newArr = [1,3,5,8,9,3,7,13];
const zeroArr = Array.from(Array(newArr.length), () => 0); 
let result = zeroArr.slice(); // Create a duplicate
result[result.length-1] = 10;

console.log(result);

Answer 2

To update the final element in an array, you can use this method:

result[result.length-1] = 10;

Check out this Stack Snippets demonstration

const newArr = [1,3,5,8,9,3,7,13];
const zeroArr = Array.from(Array(newArr.length), () => 0); 
let result = zeroArr.slice(); // Create a duplicate
result[result.length-1] = 10;

console.log(result);

Answer 3

Answer №2

To achieve this, you can utilize the Array#map method and evaluate if it is the last element in the array to return 10; otherwise, return zero.

var numbers = [2, 4, 6, 9, 12, 5, 8, 14],
    result = numbers.map((value, index, arr) => 10 * (index + 1 === arr.length));
    
console.log(result);

Answer 4

To achieve this, you can utilize the Array#map method and evaluate if it is the last element in the array to return 10; otherwise, return zero.

var numbers = [2, 4, 6, 9, 12, 5, 8, 14],
    result = numbers.map((value, index, arr) => 10 * (index + 1 === arr.length));
    
console.log(result);

Answer 5

Answer №3

Here is an alternate approach:

let numbers = [2,5,8,12,3];
let multipliedNumbers = numbers.map(num => num * 2);
console.log(numbers); // [2, 5, 8, 12, 3]
console.log(multipliedNumbers); // [4, 10, 16, 24, 6]

Answer 6

Here is an alternate approach:

let numbers = [2,5,8,12,3];
let multipliedNumbers = numbers.map(num => num * 2);
console.log(numbers); // [2, 5, 8, 12, 3]
console.log(multipliedNumbers); // [4, 10, 16, 24, 6]

Answer 7

Answer №4

Firstly, transfer the data from array newArr to another array called zeroArr. Next, insert the number 10 into a specific position in the ZeroArr using the push method. Finally, display the contents of the 'ZeroArr' by printing them out.

Answer 8

Firstly, transfer the data from array newArr to another array called zeroArr. Next, insert the number 10 into a specific position in the ZeroArr using the push method. Finally, display the contents of the 'ZeroArr' by printing them out.

Looking to swap out the final value in a JavaScript array?

Answer №1

Check out this Stack Snippets demonstration

Answer №2

Answer №3

Answer №4

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