JAVASCRIPT

javascript foreach

const avengers = ['thor', 'captain america', 'hulk'];
avengers.forEach((item, index)=>{
	console.log(index, item)
})

array.foreach

let arr = [1,2,3]

// forEach accepts a function, and each value in array is passed to the 
// function. You define the function as you would any regular
// function, you're just doing it inside the forEach loop
arr.forEach(function(value){
  console.log(value)
})

// you also have access to the index and original array:
arr.forEach(function(value, idx, array){
  console.log(idx, value, array)
})

// it's common for the arrow notation to be used: it's effectively
// the same thing but the function keyword is removed and the syntax is
// a bit different
arr.forEach((value) => {
  console.log(value)
})

for each js

const fruits = ['mango', 'papaya', 'pineapple', 'apple'];

// Iterate over fruits below

// Normal way
fruits.forEach(function(fruit){
  console.log('I want to eat a ' + fruit)
});

foreach javascript

let words = ['one', 'two', 'three', 'four'];
words.forEach((word) => {
  console.log(word);
});
// one
// two
// three
// four

js for each item in array

const array1 = ['a', 'b', 'c'];

array1.forEach(element => console.log(element));

// expected output: "a"
// expected output: "b"
// expected output: "c"

foreach javascript

var items = ["item1", "item2", "item3"]
var copie = [];

items.forEach(function(item){
  copie.push(item);
});

Javascript forEach

const products = [
    { name: 'Laptop', price: 32000, brand: 'Lenovo', color: 'Silver' },
    { name: 'Phone', price: 700, brand: 'Iphone', color: 'Golden' },
    { name: 'Watch', price: 3000, brand: 'Casio', color: 'Yellow' },
    { name: 'Aunglass', price: 300, brand: 'Ribon', color: 'Blue' },
    { name: 'Camera', price: 9000, brand: 'Lenovo', color: 'Gray' },
];
products.forEach(product => console.log(product.name));
//Output: Laptop Phone Watch Aunglass Camera

js foreach

var stringArray = ["first", "second"];

myArray.forEach((string, index) => {
  	var msg = "The string: " + string + " is in index of " + index; 
	console.log(msg);
	
	// Output:
	// The string: first is in index of 0
	// The string: second is in index of 1
});

foreach loop javascript

const numList = [1, 2, 3];

numList.forEach((number) => {
  console.log(number);
});

foreach in javascript

const avengers = ['IronMan','thor', 'captain america', 'hulk'];
avengers.forEach((item, index)=>{
	console.log(index, item)
})

foreach jas

const array1 = ['a', 'b', 'c'];

array1.forEach(element => console.log(element));

forEach()

const avengers = ['thor', 'captain america', 'hulk'];
avengers.forEach((item, index)=>{
	console.log(index, item)
})

// logs: 0 'thor', 1 'captain america', 2 'hulk'

javascript foreach

let numbers = ['one', 'two', 'three', 'four'];

numbers.forEach((num) => {
  console.log(num);
});  // one   //two //three // four

how to use foreach in javascript

var array = ["a","b","c"];
// example 1
  for(var value of array){
    console.log(value);
    value += 1;
  }

// example 2
  array.forEach((item, index)=>{
    console.log(index, item)
  })

javascript .foreach

let colors = ['red', 'blue', 'green'];
// idx and sourceArr optional; sourceArr == colors
colors.forEach(function(color, idx, sourceArr) {
	console.log(color, idx, sourceArr)
});
// Output:
// red 0 ['red', 'blue', 'green']
// blue 1 ['red', 'blue', 'green']
// green 2 ['red', 'blue', 'green']

foreach js

const arr = ["some", "random", "words"]

arr.forEach((word) => {       // takes callback and returns undefined
	console.log(word)
})

/* will print:
   some
   random
   words    */ 

js forEach method

const numbers = [28, 77, 45, 99, 27];
 
numbers.forEach(number => {  
  console.log(number);
});

javascript foreach

fruits.forEach(function(item, index, array) {
  console.log(item, index)
})
// Apple 0
// Banana 1

forEach

const arraySparse = [1,3,,7]
let numCallbackRuns = 0

arraySparse.forEach((element) => {
  console.log(element)
  numCallbackRuns++
})

console.log("numCallbackRuns: ", numCallbackRuns)

// 1
// 3
// 7
// numCallbackRuns: 3
// comment: as you can see the missing value between 3 and 7 didn't invoke callback function.

foreach javascript

let names = ['josh', 'joe', 'ben', 'dylan'];
// index and sourceArr are optional, sourceArr == ['josh', 'joe', 'ben', 'dylan']
names.forEach((name, index, sourceArr) => {
	console.log(color, idx, sourceArr)
});

// josh 0 ['josh', 'joe', 'ben', 'dylan']
// joe 1 ['josh', 'joe', 'ben', 'dylan']
// ben 2 ['josh', 'joe', 'ben', 'dylan']
// dylan 3 ['josh', 'joe', 'ben', 'dylan']

javascript foreach loop

const array = ['Element_1', 'Element_2', 'Element_3']
array.forEach((currentElement, currentElementIndex, arrayOfCurrentElement) => {
  console.log(currentElement, currentElementIndex, arrayOfCurrentElement)
})

foreach javascript

const dogs = [
 'Husky','Black Lab',
 'Australian Shepard',
 'Golden Retriever', 
 'Syberian Husky', 
 'German Shepard' 
]

dogs.forEach(function(dog) {
	console.log(dog); 
});

for each array javascript

var fruits = ["apple", "orange", "cherry"];
fruits.forEach(getArrayValues);

function getArrayValues(item, index) {
  console.log( index + ":" + item);
}
/*
result:
0:apple
1:orange
2:cherry
*/

javascript forEach

const myArray = ['hello', 1, 'thanks', 5];
myArray.forEach((item, index)=>{
	console.log(index, item)
})

javascript array foreach

arr.forEach(function (item, index, array) {
  // ... do something with item
});

forEach method Javascript

var counter = new Counter();
var numbers = [1, 2, 3];
var sum = 0;
numbers.forEach(function (e) {
    sum += e;
    this.increase();
}, counter);

console.log(sum); // 6
console.log(counter.current()); // 3
Code language: JavaScript (javascript)

.forEach in Javascript

// Arrow function
forEach((element) => { ... } )
forEach((element, index) => { ... } )
forEach((element, index, array) => { ... } )

// Callback function
forEach(callbackFn)
forEach(callbackFn, thisArg)

// Inline callback function
forEach(function callbackFn(element) { ... })
forEach(function callbackFn(element, index) { ... })
forEach(function callbackFn(element, index, array){ ... })
forEach(function callbackFn(element, index, array) { ... }, thisArg)

javaScript forEach() Method

// List all entries
let text = "";
fruits.forEach (function(value, key) {
  text += key + ' = ' + value;
})

foreach javascript

const names=["shirshak", "John","Amelia"]
//forEach is only for array and slower then for loop and for of loop 
//forEach we get function which cannot be break and continue as it is not inside 
//switch or loop.
names.forEach((name,index)=> {
console.log(name,index)//
})

foreach method of array in javascript

// foreach method of array in javascript
let numberArray = [1,2,3,4,5];
function printArrayValue(value, index){
    console.log(`value: ${value} = index: ${index}`);
}
numberArray.forEach(printArrayValue);
// Output:
// value: 1 = index: 0
// value: 2 = index: 1
// value: 3 = index: 2
// value: 4 = index: 3
// value: 5 = index: 4

foreach loop javascript

listName.forEach((listItem) => {
  Logger.log(listItem);
}):

foreach javascript

let colors = ['red', 'blue', 'green'];
// idx and sourceArr optional; sourceArr == colors
colors.forEach(function(color, idx, sourceArr) {
	console.log(color, idx, sourceArr)
});

javascript foreach

const colors = ['blue', 'green', 'white'];

function iterate(item) {
  console.log(item);
}

colors.forEach(iterate);
// logs "blue"
// logs "green"
// logs "white"

how to use the foreach method in javascript

groceries.forEach(groceryItem => console.log(groceryItem));

javascript foreach

// Arrow function
forEach((element) => { /* ... */ })
forEach((element, index) => { /* ... */ })
forEach((element, index, array) => { /* ... */ })

javascript foreach

var arr = [1, 2, 3, 4];

arr.forEach(function(element) {
  console.log(element);
});

javascript for each

// array for the forEach method
let grades = [13, 12, 14, 15]

// for each loop
grades.forEach(function(grade) {
	console.log(grade) // loops and logs every grade of the grades array
})

js foreach

for (let i in arr) {
	console.log(i);
}

.forEach in Javascript

Array.prototype.forEach.call(node.childNodes, (child) => {
    // Do something with `child`
});

javaScript forEach() Method

// Create a Set
const letters = new Set(["a","b","c"]);

// List all Elements
let text = "";
letters.forEach (function(value) {
  text += value;
})

js foreach

for (const element of theArray) {
    // ...use `element`...
}

foreach js

angular.forEach(obj1.results, function(result1) {
    angular.forEach(obj2.results, function(result2) {
        if (result1.Value === result2.Value) {
            //do something
        }
    });
});

//exact same with a for loop
for (var i = 0; i < obj1.results.length; i++) {
    for (var j = 0; j < obj2.results.length; j++) {
        if (obj1.results[i].Value === obj2.results[j].Value) {
            //do something
        }
    }
}

ForEach

let data = ["A", "B", "C", "D"];
function process(element)
{
    console.log(element);
}
// With named Function
data.forEach(process);

// With Lambda/anonymous Function
data.forEach((element) => console.log(element));

javascript array foreach

const fruits = ['apple', 'orange', 'banana', 'mango'];
fruits.forEach((item, index)=>{
	console.log(index, item)
});

foreach

array.foreach((item)=>{
				console.log(item);
             });

foreach javascript

Used to execute the same code on every element in an array
Does not change the array
Returns undefined

mdn foreach

arr.forEach(callback(currentValue [, index [, array]])[, thisArg])

foreach

const { chromium } = require("playwright");
const fs = require("fs");

(async () => {
  const browser = await chromium.launch();
  const page = await browser.newPage();
  await page.goto("https://danube-webshop.herokuapp.com");
  const content = await page.evaluate(() => {
    let data = [];

    let books = document.querySelectorAll(".preview");
    books.forEach((book) => {
      let title = book.querySelector(".preview-title").innerText;
      let author = book.querySelector(".preview-author").innerText;
      let price = book.querySelector(".preview-price").innerText;
      data.push({
        title,
        author,
        price,
      });
    });
    return data;
  });

  const jsonData = JSON.stringify(content);
  fs.writeFileSync("books.json", jsonData);
  await browser.close();
})();

Using the forEach function In JavaScript

 
		  let text = "";
function add()
		  { 
			  var node = Node.prototype;
			 nodeList =  NodeList.prototype;
			 const xxx = ["q", "w", "e", "r", "t"];
			 xxx.forEach(change);
			 console.log(xxx);
			 console.log(text);
             /*notice the array does not change but text does*/
	 }
	 function change(item, index) {
		 text += item+index;
	 }

forEach()

const colors = ['green', 'yellow', 'blue'];
colors.forEach((item, index) => console.log(index, item));
// returns the index and the every item in the array
// 0 "green"
// 1 "yellow"
// 2 "blue"

js foreach syntax

someArray.forEach(function(element, index, array) { /* function body */ }, thisArg)

javascript foreach

arr.forEach(function callback(currentValue, index, array) {
    // tu iterador
}[, thisArg]);

foreach in javascript

<p>forEach() calls a function for each element in an array:</p>

<p>Multiply the value of each element with 10:</p>

<p id="demo"></p>

<script>
const numbers = [65, 44, 12, 4];
numbers.forEach(myFunction)

document.getElementById("demo").innerHTML = numbers;

function myFunction(item, index, arr) {
  arr[index] = item * 10;
}
</script>

forEach() calls a function for each element in an array:

Multiply the value of each element with 10:

650,440,120,40