Simplify Repetitive Tasks with a forEach Loop

Arrays also work closely together with another common feature in 0:00 JavaScript, loops. 0:03 Loops are a powerful tool in programming. 0:05 A loop is a way to repeat the same actions a certain number of times. 0:07 Now, there are many different types of loops available to use in JavaScript. 0:10 But they all essentially do the same thing, 0:14 they repeat an action a given number of times. 0:16 So here I'll cover two common ways you might see loops written in modern 0:18 JavaScript. 0:22 First is the for-each loop. 0:23 For-each is simply a loop that accesses each item in an array. 0:25 So for example, instead of manually accessing each element in an array by 0:30 index like I showed you earlier, we can use a loop to do it for us. 0:34 So we could, for instance, write a loop that grabs each movie title in the movies 0:38 array, and converts them into an HTML list with links the user can click. 0:44 To write a for-each loop, you first put the variable name of the array, 0:48 then .forEach and a set of parentheses. 0:54 Inside the parentheses, you provide for-each a function to run and 0:58 complete once for each item inside the array. 1:02 You'll hear this type of function referred to as a callback function. 1:06 For this example, I'll write a function that pops up an alert box for 1:11 each movie title in the movies array. 1:15 The function will take one parameter, I'll call it movie. 1:18 The parameter movie represents the current element or 1:23 movie title being processed here in the array. 1:28 And notice that there's no name after the function keyword this time, 1:32 because it has no name. 1:36 It's called an anonymous function. 1:37 You'll often use anonymous functions to pass functions as parameters 1:39 to another function. 1:43 So inside the body of the function, or between the curly braces, 1:45 we can do whatever we want with each item in the array. 1:48 So I'm gonna pop up an alert dialogue box for each movie title in the array. 1:51 I'll type alert, and pass it movie. 1:57 So forEach is going to call the function passed to it, 2:02 for each element in the movies array. 2:07 When the function is called, a movie title is passed into the movie argument, 2:12 then the next, the next, and so on. 2:18 The loop stops when it has reached the end of the movies array, and 2:22 there are no more movie titles to pop up in the alert box. 2:26 So this is just a simple example of how loops in JavaScript 2:30 manage the process of accessing each element in an array for you. 2:33 Many programmers find for-each easier to read 2:37 than some of the other ways of writing loops. 2:40 The code in a for-each loop is easier to and 2:42 understand, and usually involves less codes. 2:45