Array.prototype.shift()
The JavaScript array method .shift()
will remove the first element from an array and return that value. This will also change the length of the array
Syntax
var array = [1, 2, 3, 4];
array.shift();
Description
.shift()
will remove the element at index 0 of the array upon which it is called. It then returns the removed value and shifts all remaining elements down by 1 index value.
.shift()
will return undefined
if the array it is called on contains no elements.
Examples
Shifting the first value from an array
var array = [1, 2, 3, 4, 5];
console.log(array);
// Console will output 1, 2, 3, 4, 5
array.shift();
// If we console.log(array.shift()); the console would output 1.
console.log(array);
/* Console will output 2, 3, 4, 5 and
the variable array now contains the set [2, 3, 4, 5] where
each element has been moved down 1 index value. */
Source MDN