JavaScript | Array shift()

arr.shift() function removes the first element of the array thus reducing the size of the original array by 1.

Syntax:
arr.shift()

Arguments

This function does not take any argument.

Return value

This function returns the removed first element of the array.

If the array is empty then this function returns undefined.

Note: This function can also be used with other javascript objects that behave like the array.

Example 1:

var arr = [34, 234, 567, 4];
print(arr.shift());
print(arr);

Output:

34
234,567,4

In this example the function shift() removes the first element of the array, therefore it returns 34.

Example 2:

var arr = [];
print(arr.shift());
print(arr);

Output:

undefined

In this example the function shift() tries to remove the first element of the array, but the array is empty, therefore it returns undefined.

Codes for the above function are provided below:

Program 1:

Output:

34
234,567,4

Program 2:

Output:

undefined