In this lesson we look at Codecademy's Learn JavaScript lesson, Nested Loops, in this JavaScript tutorial video called, "Use a Nested Loop to Find Mutual Followers, Nested Loops Explained, Accessing Nested Arrays with JS" We learn how to loop through 2 arrays and compare what is in them. We learn that we are able to use a nested for loop to iterate through both of our arrays and compare the contents within both arrays. Whenever the elements within our arrays match, we can push those matching elements to an empty array that we call mutual friends. This lesson tries to teach us the fundamentals of using a nested loop to iterate through list data quickly. We are able to go through all the contents of 2 arrays and compare data found within them, and in this lesson specifically, we are able to find mutual friends and save them to their own array, for later use. Understanding how a nested loop works and when to use a nested loop is an important skill to learn in javascript. Understanding looping through arrays and the fact that the outer loop runs once, then the inner loop will run completely before coming to the next element on the outer loop is a key fundamental to understanding nested loops. A loop inside a loop allows us to check vast lists against each other and allows us to save important data from both lists, as we see necessary. Make sure to understand nested loops before moving on to the next lesson.
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