Lesson 22
Courses / JavaScript for Complete Beginners
Adding / Removing Elements at the End of JavaScript Array (push and pop)

Video Transcript

Welcome back to NDK Tech World. Let's continue our study of JavaScript arrays. So let me clear the console. I'm using Google Chrome this time. So we learned how to access elements in an array, right? We had the names array with three elements and to get each element you just use the brackets where brackets in the index, right? Get John, get Ann and get Andrew. So the index always starts from zero. Now how can we modify this array? That's what we're going to learn in this lesson. We're going to talk about push and about pop. So push and pop, these are the methods we can use to change the array, either to insert an item or to remove an item. Now push and pop, as we're going to see, they add, you add either add to the end of the array or if you remove from the end. So it's a little bit of constraint there. So let's get started. Suppose I have this names and I want to add a new name. So I can say names and I put a dot push. This is the method, okay? It's a method called push. Then you put two parentheses because it's a function call. And then you need to tell it, okay, what do you want to push? It could be multiple things, but let's start like starts simple and just push one name. So you can push another person. I don't know what to call the name or just say a new name. Let's see what happens. So I say names dot push a new name. And I got this four back. The return value here, this is called the return value of the result of this expression. So this is just telling you how many elements are now present in the array names. If you inspect names like so, you're going to notice that not only John and an Android there, but also a new name has been added to the end of the list. So that's what push does. It adds a new element at the end of the list. Okay. Now we have four elements. Now let's learn how to remove an element from the end of the array. That's called a pop operation. So if I say names dot pop, remember the parentheses, because it's a function call. In this case, I don't need any arguments. I just want this list called names to pop the last element. So if I say that, I actually get as a return value from this function call, the element that was popped. But if you inspect names now, you can see that new name is no longer there. So it has been removed from the end of the array and was given as a return value of the pop operation. Okay, so that's push and pop. Let's review what we did. So we have an array called names that holds people's names. This case, we start off with three names. Then we wanted to add a new name called new name to the end of the list. We use the push operation, it always pushes to the end. Okay. And then we learn how to remove the last element in the array, we're using the pop operation. So push and pop always operate at the end of the array. Okay, keep that in mind. So I think we're good for this video and until the next time, see you.
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