In this article, we will create a zero-filled array in JavaScript. A zero-filled array is an array whose value at each index is zero. For this, we have a few methods such as we can use:
- Array fill() method
- Array.from() method.
- Array constructors can also be used to create a zero-filled array.
- Array using for loop
Method 1: Array.prototype.fill.
The fill() method is used to change the elements of the array to a static value from the initial index (by default 0) to the end index (by default array.length). The modified array is returned.
Syntax:
fill(value, start, end)
Example 1: The following code snippet demonstrates the fill() method with 0 value.
Javascript
const arr = new Array(5).fill(0);console.log(arr); |
Output:
[0, 0, 0, 0, 0]
Array constructor takes the size of an array as a parameter if we pass one argument into it. fill() method takes the value we want to fill in the array.
Note: JavaScript fill() method is available since ES6.
Method 2: Using Apply() and Map().
In the below example, we use apply() method to create an array of 5 elements that can be filled with the map() method. In the map() method, we pass in a callback that returns 0 to fill all the indexes with zeros.
Example: Array.apply() method is used to create an empty array in which we can use the map() method to store each element as key-value pair.
Javascript
const arr = Array.apply(null, Array(5)).map(() => 0);console.log(arr); |
Output:
[0, 0, 0, 0, 0]
Method 3: Using Array.from().
This method is used to create a new,shallow-copied array from an array-like or iterable object.
Syntax:
Array.from(arrayLike, (element) => { /* ... */ } )
Example: In the below example, Array.from() is called which lets us map an empty array of size 5 to an array with some elements inside. The second argument is a callback that returns 0 which is used to fill the array.
Javascript
const arr = Array.from(Array(5), () => 0)console.log(arr); |
Output:
[0, 0, 0, 0, 0]
The same result can be obtained by passing an object with the length property using the Array.from() method.
Javascript
const arr = Array.from({ length: 5}, () => 0)console.log(arr); |
Output:
[0, 0, 0, 0, 0]
Method 4: Using for loop:
Example: In this example, we will use the for loop for creating a zero-filled array.
Javascript
let zeroArr = []for (i = 0; i < 5; i++) { zeroArr[i] = 0;}console.log(zeroArr); |
Output:
[ 0, 0, 0, 0, 0 ]
