Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.Aprenda Array Methods and Manipulation | Variables and Data Types in JavaScript
Introduction to JavaScript

bookArray Methods and Manipulation

Arrays are versatile for storing and retrieving data. Retrieving data using square brackets [] is called indexing.

let arr = [1, 2, 3, 4, 5, 6];
arr[3] // This is indexing

However, there are various methods available for working with arrays.

Adding Elements

There are different ways to add elements to an array.

Push

The push() method adds a new value to the end of the array:


              
1234567

            
let arr = [1, 2, 3];

arr.push(4);
arr.push(5);
arr.push(6);

console.log(arr);
copy

Unshift

The unshift() method works like the push() method, but it inserts the value at the beginning of the array.


              
123456

            
let arr = [1, 2, 3];
console.log("Array:", arr);

arr.unshift(222);  // Insert element at the start

console.log("Array:", arr);
copy

Indexing

You can append a new value by indexing:


              
123456

            
let arr = [1, 2];

arr[2] = 3;
arr[3] = 4;

console.log(arr);
copy

Indexing allows you to assign a value to a specified index, reassign a previous value, and more:


              
12345

            
let arr = [1, 2, 3];

arr[0] = 4;

console.log("Array:", arr);
copy

To create a new element in the array without mistakes, you can use the push(value) method or the arr[arr.length] = value expression:


              
12345678910111213

            
let myArray = [];

myArray[myArray.length] = "indexing";
console.log("After first indexing:", myArray);

myArray.push("pushing");
console.log("After first pushing:", myArray);

myArray[myArray.length] = "indexing";
console.log("After second indexing:", myArray);

myArray.push("pushing");
console.log("After second pushing:", myArray);
copy

Deleting Elements

Sometimes, you may need to delete elements from an array. This can be done in different ways.

Pop

The pop() method deletes the last element in an array and allows you to save it to another variable:


              
1234567

            
let arr = [11, 22, 33, 44];
console.log("Array:", arr);

let x = arr.pop(); // Remove and save the last element in `arr` to variable `x`

console.log("Popped element:", x);
console.log("Array now:", arr);
copy

Shift

The shift() method works like pop(), but it removes the first element from an array:


              
123456789101112

            
let arr = [11, 22, 33, 44, 55, 66];
console.log("Array:", arr);

let popped = arr.pop();  // Remove the last element

console.log("Popped:", popped);
console.log("Array:", arr);

let shifted = arr.shift();  // Remove the first element

console.log("Shifted:", shifted);
console.log("Array:", arr);
copy

1. How can we add an element to the end of the array?

2. How can we remove the last element in the array?

question mark

How can we add an element to the end of the array?

Select the correct answer

question mark

How can we remove the last element in the array?

Select the correct answer

Tudo estava claro?

Como podemos melhorá-lo?

Obrigado pelo seu feedback!

Seção 2. Capítulo 7

Pergunte à IA

expand

Pergunte à IA

ChatGPT

Pergunte o que quiser ou experimente uma das perguntas sugeridas para iniciar nosso bate-papo

Awesome!

Completion rate improved to 2.33

bookArray Methods and Manipulation

Deslize para mostrar o menu

Arrays are versatile for storing and retrieving data. Retrieving data using square brackets [] is called indexing.

let arr = [1, 2, 3, 4, 5, 6];
arr[3] // This is indexing

However, there are various methods available for working with arrays.

Adding Elements

There are different ways to add elements to an array.

Push

The push() method adds a new value to the end of the array:


              
1234567

            
let arr = [1, 2, 3];

arr.push(4);
arr.push(5);
arr.push(6);

console.log(arr);
copy

Unshift

The unshift() method works like the push() method, but it inserts the value at the beginning of the array.


              
123456

            
let arr = [1, 2, 3];
console.log("Array:", arr);

arr.unshift(222);  // Insert element at the start

console.log("Array:", arr);
copy

Indexing

You can append a new value by indexing:


              
123456

            
let arr = [1, 2];

arr[2] = 3;
arr[3] = 4;

console.log(arr);
copy

Indexing allows you to assign a value to a specified index, reassign a previous value, and more:


              
12345

            
let arr = [1, 2, 3];

arr[0] = 4;

console.log("Array:", arr);
copy

To create a new element in the array without mistakes, you can use the push(value) method or the arr[arr.length] = value expression:


              
12345678910111213

            
let myArray = [];

myArray[myArray.length] = "indexing";
console.log("After first indexing:", myArray);

myArray.push("pushing");
console.log("After first pushing:", myArray);

myArray[myArray.length] = "indexing";
console.log("After second indexing:", myArray);

myArray.push("pushing");
console.log("After second pushing:", myArray);
copy

Deleting Elements

Sometimes, you may need to delete elements from an array. This can be done in different ways.

Pop

The pop() method deletes the last element in an array and allows you to save it to another variable:


              
1234567

            
let arr = [11, 22, 33, 44];
console.log("Array:", arr);

let x = arr.pop(); // Remove and save the last element in `arr` to variable `x`

console.log("Popped element:", x);
console.log("Array now:", arr);
copy

Shift

The shift() method works like pop(), but it removes the first element from an array:


              
123456789101112

            
let arr = [11, 22, 33, 44, 55, 66];
console.log("Array:", arr);

let popped = arr.pop();  // Remove the last element

console.log("Popped:", popped);
console.log("Array:", arr);

let shifted = arr.shift();  // Remove the first element

console.log("Shifted:", shifted);
console.log("Array:", arr);
copy

1. How can we add an element to the end of the array?

2. How can we remove the last element in the array?

question mark

How can we add an element to the end of the array?

Select the correct answer

question mark

How can we remove the last element in the array?

Select the correct answer

Tudo estava claro?

Como podemos melhorá-lo?

Obrigado pelo seu feedback!

Seção 2. Capítulo 7
some-alt