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JavaScript map() method in 7 minutes! ๐Ÿ—บ๏ธ

123.8K views on YouTube

00:00:00 introduciton
00:00:16 example 1
00:02:13 example 2
00:03:58 example 3

// .map() = accepts a callback and applies that function
// to each element of an array, then return a new array

// ———— EXAMPLE 1 ————
const numbers = [1, 2, 3, 4, 5];
const squared = numbers.map(square);
const cubed = numbers.map(cube);

console.log(cubed);

function square(element){
return Math.pow(element, 2);
}

function cube(element){
return Math.pow(element, 3);
}

// ———— EXAMPLE 2 ————
const students = [“Spongebob”, “Patrick”, “Squidward”, “Sandy”];
const studentsUpper = students.map(upperCase);
const studentsLower = students.map(lowerCase);

console.log(studentsLower);

function upperCase(element){
return element.toUpperCase();
}

function lowerCase(element){
return element.toLowerCase();
}

// ———— EXAMPLE 3 ————
const dates = [“2024-1-10”, “2025-2-20”, “2026-3-30”];
const formattedDates = dates.map(formatDates);

console.log(formattedDates);

function formatDates(element){
const parts = element.split(“-“);
return `${parts[1]}/${parts[2]}/${parts[0]}`;
}