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)
})
const fruits = ['mango', 'papaya', 'pineapple', 'apple'];
// Iterate over fruits below
// Normal way
fruits.forEach(function(fruit){
console.log('I want to eat a ' + fruit)
});
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
});
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)
})
const arr = ["some", "random", "words"]
arr.forEach((word) => { // takes callback and returns undefined
console.log(word)
})
/* will print:
some
random
words */
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)//
})
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;
}
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"
<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