Array in JavaScript

In JavaScript, an array is a special variable used to store multiple values in a single variable.

1. How to create an array

let fruits = ["Apple", "Mango", "Orange", "Banana"];

console.log(fruits);

Output:

["Apple", "Mango", "Orange", "Banana"]

2. Access array elements

Array indexing starts from 0, not 1.
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let fruits = ["Apple", "Mango", "Orange", "Banana"];

console.log(fruits[0]); // Apple
console.log(fruits[1]); // Mango
console.log(fruits[2]); // Orange
console.log(fruits[3]); // Banana

3. Important array properties and methods

let fruits = ["Apple", "Mango", "Orange"];

console.log(fruits.length);

Output: 3
push() — add an element at the end

let fruits = ["Apple", "Mango"];

fruits.push("Orange");

console.log(fruits);

Output: ["Apple", "Mango", "Orange"]

pop() — remove the last element

let fruits = ["Apple", "Mango", "Orange"];

fruits.pop();

console.log(fruits);

Output: ["Apple", "Mango"]

unshift() — add an element at the beginning

let fruits = ["Mango", "Orange"];

fruits.unshift("Apple");

console.log(fruits);

Output: ["Apple", "Mango", "Orange"]

shift() — remove the first element

let fruits = ["Apple", "Mango", "Orange"];

fruits.shift();

console.log(fruits);

Output: ["Mango", "Orange"]

4. Update an array element

let fruits = ["Apple", "Mango", "Orange"];

fruits[1] = "Banana";

console.log(fruits);

Output:["Apple", "Banana", "Orange"]
The element at index 1 changes from "Mango" to "Banana".

5. Loop through an array
Use a for loop to access every element.

let fruits = ["Apple", "Mango", "Orange"];

for (let i = 0; i < fruits.length; i++) {
    console.log(fruits[i]);
}

Output :
Apple
Mango
Orange

1. forEach() — execute code for each element

let fruits = ["Apple", "Mango", "Orange"];

fruits.forEach(function(fruit) {
    console.log(fruit);
});

This prints every fruit without manually managing the index.

1. map()— create a new array A JavaScript Map is an object that can store collections of key-values

let numbers = [10, 20, 30, 40];

let result = numbers.map(function(num) {
    return num * 2;
});

console.log(result);

plaintext
Output : [20, 40, 60, 80]

1. filter() — select elements that match a condition

let numbers = [10, 15, 20, 25, 30];

let result = numbers.filter(function(num) {
    return num >= 20;
});

console.log(result);

plaintext
Output : [20, 25, 30]

9. Array of objects
This is especially useful for your JavaScript product management practice.

let products = [
    { brand: "Samsung", price: 25000 },
    { brand: "Apple", price: 50000 },
    { brand: "Vivo", price: 18000 }
];

console.log(products[0].brand); // Samsung
console.log(products[1].price); // 50000

Each array element is an object containing product information.