JavaScript Map, Reduce, and Filter Functions

 const numbers = [1, 2, 3, 4, 5, 6, 7];

//Transforms each element - map creates a new array by applying a function to every element of the original array.

//Retun length of same array size.

const double = numbers.map(x => x * 2);

console.log(double);

const evenNumber = numbers.map(x => x % 2 === 0);

console.log(evenNumber);

// Selects certain elements - filter creates a new array with only the elements

that pass a test (predicate function).

//Retun length of same or different array size.

const filerResult = numbers.filter(x => x > 3);

console.log(filerResult);

//Combine of filter and Map function

const combine = numbers.filter(x => x > 3).map(y => y * 2);

console.log(combine);

//The reduce() method reduces an array to a single value by applying a function

accumulatively (from left to right) to all elements.

// Reduces array to a single value (e.g., sum)

const sum = numbers.reduce((accumulator, current) => accumulator + current, 0);

console.log(sum);