What is an Array?

An array is a special variable, which can hold more than one value at a time. It is a collection of elements stored in a single variable.

Creating an Array

There are multiple ways to create an array in JavaScript:

  1. Using an array literal:

      let fruits = ["Apple", "Banana", "Cherry"];
console.log(fruits); // ["Apple", "Banana", "Cherry"]

  2. Using the Array constructor:

      let fruits = new Array("Apple", "Banana", "Cherry");
console.log(fruits); // ["Apple", "Banana", "Cherry"]

Accessing Array Elements

You can access elements of an array by their index:

  let fruits = ["Apple", "Banana", "Cherry"];
console.log(fruits[0]); // "Apple"
console.log(fruits[1]); // "Banana"
console.log(fruits[2]); // "Cherry"

Modifying Array Elements

You can modify elements of an array by their index:

  let fruits = ["Apple", "Banana", "Cherry"];
fruits[1] = "Blueberry";
console.log(fruits); // ["Apple", "Blueberry", "Cherry"]

Array Methods

  1. push()

    Adds new elements to the end of an array:

      let fruits = ["Apple", "Banana"];
fruits.push("Cherry");
console.log(fruits); // ["Apple", "Banana", "Cherry"]

  2. pop()

    Removes the last element of an array:

      let fruits = ["Apple", "Banana", "Cherry"];
let lastFruit = fruits.pop();
console.log(fruits); // ["Apple", "Banana"]
console.log(lastFruit); // "Cherry"

  3. shift()

    Removes the first element of an array:

      let fruits = ["Apple", "Banana", "Cherry"];
let firstFruit = fruits.shift();
console.log(fruits); // ["Banana", "Cherry"]
console.log(firstFruit); // "Apple"

  4. unshift()

    Adds new elements to the beginning of an array:

      let fruits = ["Banana", "Cherry"];
fruits.unshift("Apple");
console.log(fruits); // ["Apple", "Banana", "Cherry"]

  5. length

    Returns the length of an array:

      let fruits = ["Apple", "Banana", "Cherry"];
console.log(fruits.length); // 3

  6. concat()

    Joins two or more arrays:

      let fruits = ["Apple", "Banana"];
let moreFruits = ["Cherry", "Date"];
let allFruits = fruits.concat(moreFruits);
console.log(allFruits); // ["Apple", "Banana", "Cherry", "Date"]

  7. slice()

    Returns selected elements in an array, as a new array:

      let fruits = ["Apple", "Banana", "Cherry", "Date"];
let someFruits = fruits.slice(1, 3);
console.log(someFruits); // ["Banana", "Cherry"]

  8. splice()

    Adds/removes elements from an array:

      let fruits = ["Apple", "Banana", "Cherry"];
fruits.splice(1, 1, "Blueberry", "Kiwi");
console.log(fruits); // ["Apple", "Blueberry", "Kiwi", "Cherry"]

  9. forEach()

    Calls a function once for each array element:

      let fruits = ["Apple", "Banana", "Cherry"];
fruits.forEach(function(fruit) {
console.log(fruit);
});
// Output:
// "Apple"
// "Banana"
// "Cherry"

  10. map()

    Creates a new array with the result of calling a function for every array element:

      let numbers = [1, 2, 3];
let squaredNumbers = numbers.map(function(number) {
return number * number;
});
console.log(squaredNumbers); // [1, 4, 9]