Array iteration methods in javascript

🔹 1. forEach()
Executes a function for each element in the array
Does not return a new array.

Program

let numbers = [1, 2, 3];

numbers.forEach(function(num) {
console.log(num * 2);
});

Output:

2
4
6

1. map() Creates a new array by transforming each element

JavaScript

let numbers = [1, 2, 3];

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

console.log(doubled);

👉 Output:

[2, 4, 6]

1. filter()

Returns a new array with elements that match a condition

JavaScript

let numbers = [1, 2, 3, 4];

let even = numbers.filter(function(num) {
return num % 2 === 0;
});

console.log(even);

Output:

[2, 4]

1. reduce()

Reduces array to a single value

JavaScript

let numbers = [1, 2, 3, 4];

let sum = numbers.reduce(function(total, num) {
return total + num;
}, 0);

console.log(sum);

Output:

10

1. find()

Returns the first element that satisfies condition

JavaScript

let numbers = [1, 3, 5, 8];

let result = numbers.find(function(num) {
return num > 4;
});

console.log(result);

Output:

5

1. some()

Returns true if any element satisfies condition

JavaScript

let numbers = [1, 2, 3];

let hasEven = numbers.some(function(num) {
return num % 2 === 0;
});

console.log(hasEven);

Output:

true

1. every()

Returns true if all elements satisfy condition

JavaScript

let numbers = [2, 4, 6];

let allEven = numbers.every(function(num) {
return num % 2 === 0;
});

console.log(allEven);

Output:

true