for each function JS code example

Example 1: javascript foreach

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

Example 2: foreach jas

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

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

Example 3: 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']

Example 4: 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.

Example 5: for each javascript

const movies = [
{name: "A New Hope", director: "George Lucas", release: "1977-05-25", episodeID: 4},
{name: "Attack of the Clones", director: "George Lucas", release: "2002-05-16", episodeID: 2},
{name: "Return of the Jedi", director: "Richard Marquand", release: "1983-05-25", episodeID: 6},
{name: "Revenge of the Sith", director: "George Lucas", release: "2005-05-19", episodeID: 3},
{name: "The Empire Strikes Back", director: "Irvin Kershner", release: "1980-05-17", episodeID: 5},
{name: "The Phantom Menace", director: "George Lucas", release: "1999-05-19", episodeID: 1}     
]
movies.forEach((movies) => {
  console.log(movies.name);
});
/*A New Hope
Attack of the Clones
Return of the Jedi
Revenge of the Sith
The Empire Strikes Back
The Phantom Menace*/

Example 6: foreach javascript

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