JavaScript forEach() method in 8 minutes! ➿

Bro Code
Bro Code
22,835
0
Published 2023-11-09
00:00:00 introduction
00:00:18 example 1
00:03:58 example 2
00:07:37 conclusion

// forEach() = method used to iterate over the elements
// of an array and apply a specified function (callback)
// to each element

// array.forEach(callback)
// element, index, array are provided

// ------------- EXAMPLE 1 -------------

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

numbers.forEach(cube);
numbers.forEach(display);

function double(element, index, array){
array[index] = element * 2;
}

function triple(element, index, array){
array[index] = element * 3;
}

function square(element, index, array){
array[index] = Math.pow(element, 2);
}

function cube(element, index, array){
array[index] = Math.pow(element, 3);
}

function display(element){
console.log(element);
}

// ------------- EXAMPLE 2 -------------

let fruits = ["apple", "orange", "banana", "coconut"];

fruits.forEach(capitalize);
fruits.forEach(display);

function upperCase(element, index, array){
array[index] = element.toUpperCase();
}

function lowercase(element, index, array){
array[index] = element.toLowerCase();
}

function capitalize(element, index, array){
array[index] = element.charAt(0).toUpperCase() + element.slice(1);
}

/*
function display(element){
console.log(element);
}
*/
All Comments (13)
  • @BroCodez
    // forEach() = method used to iterate over the elements // of an array and apply a specified function (callback) // to each element // array.forEach(callback) // element, index, array are provided // -------------- EXAMPLE 1 -------------- const numbers = [1, 2, 3, 4, 5]; numbers.forEach(cube); numbers.forEach(display); function double(element, index, array){ array[index] = element * 2; } function triple(element, index, array){ array[index] = element * 3; } function square(element, index, array){ array[index] = Math.pow(element, 2); } function cube(element, index, array){ array[index] = Math.pow(element, 3); } function display(element){ console.log(element); } // -------------- EXAMPLE 2 -------------- let fruits = ["apple", "orange", "banana", "coconut"]; fruits.forEach(capitalize); fruits.forEach(display); function upperCase(element, index, array){ array[index] = element.toUpperCase(); } function lowercase(element, index, array){ array[index] = element.toLowerCase(); } function capitalize(element, index, array){ array[index] = element.charAt(0).toUpperCase() + element.slice(1); } /* function display(element){ console.log(element); } */
  • @vctorroferz
    Hey it is just incredible how you can just explain these concepts in just 8 minutes! thanks so much for makeing these videos ! :)
  • @mjylove2
    amazing explanation ! understood!
  • @UncannyPotato69
    bro, i don't get what you mean when you say the element, index and array are already provided for? please help me understand what you mean by it. and thanks for making such cool tutorials