JavaScript Array fill() method

The fill() method in JavaScript is used to fill all the elements of an array with a static value. This method modifies the array in place, meaning that it changes the existing array instead of creating a new one.

Here is an example of how the fill() method works:

const array1 = [1, 2, 3, 4, 5];

// fill the array with the value 0
const result = array1.fill(0);

// the result will be: [0, 0, 0, 0, 0]

In the code example above, we first declare an array called array1 that contains the numbers 1 through 5. We then use the fill() method to fill the array with the value 0. The fill() method takes a single argument, which is the value that should be used to fill the array. In this case, we use 0 as the fill value.

As a result of calling the fill() method, the array1 array is modified in place and now contains the following elements: 0, 0, 0, 0, 0.

In addition to filling the entire array with a static value, the fill() method also allows you to specify a start index and an end index to specify a range of elements that should be filled. For example:

const array1 = [1, 2, 3, 4, 5];

// fill the middle three elements with the value 0
const result = array1.fill(0, 1, 4);

// the result will be: [1, 0, 0, 0, 5]

In the code example above, we use the fill() method to fill the middle three elements of the array1 array with the value 0. We specify 1 as the start index and 4 as the end index, which means that the fill() method will only affect the elements at indices 1 through 3 (inclusive) of the array.

As a result of calling the fill() method, the array1 array is modified in place and now contains the following elements: 1, 0, 0, 0, 5.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: