TypeScript Array shift()
Syntax & Examples
Array.shift() method
The shift() method removes the first element from an array and returns that removed element. This method changes the length of the array.
Syntax of Array.shift()
The syntax of Array.shift() method is:
shift(): T | undefined
This shift() method of Array removes the first element from an array and returns it.
Return Type
Array.shift() returns value of type T
the type of element removed from the array, or undefined
.
✐ Examples
1 Using shift() to remove the first element
The shift() method can be used to remove the first element from an array.
For example,
- Create an array
arr
with numeric values [1, 2, 3, 4, 5]. - Use
shift()
to remove the first element of the array. - Store the removed element in
removedElement
. - Log
removedElement
and the modified arrayarr
to the console.
TypeScript Program
const arr = [1, 2, 3, 4, 5];
const removedElement = arr.shift();
console.log(removedElement); // 1
console.log(arr); // [2, 3, 4, 5]
Output
1 [2, 3, 4, 5]
2 Using shift() on an empty array
The shift() method returns undefined when called on an empty array.
For example,
- Create an empty array
arr
. - Use
shift()
to attempt to remove the first element of the array. - Store the result in
result
. - Log
result
and the modified arrayarr
to the console.
TypeScript Program
const arr = [];
const result = arr.shift();
console.log(result); // undefined
console.log(arr); // []
Output
undefined []
3 Using shift() with mixed data types
The shift() method can be used on an array with mixed data types to remove the first element.
For example,
- Create an array
arr
with mixed values [true, 42, 'hello']. - Use
shift()
to remove the first element of the array. - Store the removed element in
removedElement
. - Log
removedElement
and the modified arrayarr
to the console.
TypeScript Program
const arr = [true, 42, 'hello'];
const removedElement = arr.shift();
console.log(removedElement); // true
console.log(arr); // [42, 'hello']
Output
true [42, 'hello']
Summary
In this TypeScript tutorial, we learned about shift() method of Array: the syntax and few working examples with output and detailed explanation for each example.