Welcome to NVK Tech World. I have an exercise for you and that's gonna involve control flow of the NIF, ELSE block and arrays. So let's suppose we have an array with three elements and each element is a number. Let's think about something like phone numbers. So say we have this array right here. It's an array with three elements. First element is 1, 2, 3, number 1, 2, 3, then second element number 4, 5, 6, third number is number 7891. So let's imagine these are parts of a phone number. So you're processing many phone numbers in your program and you want to check for the area code. I'm just making these numbers up by the way. They're not necessarily something specific. So let's say the first element of this array, the whole array itself is a phone number and this is the part of the phone number that we're interested in. The first part is going to be the area code. In this case, this is the area code 1, 2, 3. Now suppose we want to check in our program if we want to check to find if the phone number is 1, 2, 3. We want to display, do something. In this case, we're just going to display a message saying the phone number is 1, 2, 3, something like that. Found phone number 1, 2, 3. Otherwise, we don't really care. We're just going to say this phone number just doesn't match 1, 2, 3. So let's add, store this array in a variable. I'm going to use let in case I need to change it later. Let, let me say, let's call it phone number part about that. So this variable phone number part, I use the camel case naming convention by the way, if you haven't forgotten, naming camel case always starts off lowercase for the very first letter, but every following new word, the first letter has to be capitalized. All right. Now this variable holds this array of phone number parts. We're interested in the first element of the array, which is the area code. Like I want you to right here make console log found phone number one of area code 1, 2, 3. If the phone number parts, the given phone number parts in this case, I already defined it here. If it is, you assume it's going to be stored in this variable, by the way, doesn't have to be this value, I'll be changing it. So it's changeable, but use the same variable name. Then if it's, if you find that guy to be the value one, two, three, print out a message found phone number area code one, two, three. Otherwise, if you did not find one, two, three for the for the area code, just say a message. The phone number area code does not match. Okay, so that's an exercise for you. Just as a hint, you're going to use the if statement. You can pause the video and trade out. And then we're going to do the solution after that. So how did it go? So we have to check first. If this area code is 123, how to do that, we're going to do a comparison. So phone number parts is the variable that holds all these three elements. How can we get the first element? This is an array. So to get access elements of an array, you can use the brackets square brackets, right after the name of the array, and you have to give it the index index always counts from zero. So the first element here has index zero. And then this guy has index one and this guy index two and so on. So we are only interested in the first one. So it's going to be zero. There you go. So we grab 123. And now what we're going to do is we have to check if this guy is indeed 123. We're going to make a comparison of equality. We're going to do triple equals. I always use triple equals initially. I always want to test for strict equality. In rare cases, do I want to use the double equals? Okay, it's just to make it strict. It's better and causes you to have less bucks down the less bugs down the road. So be aware that I will always start with the triple equals to be a strict equality. So we're going to check if that guy is the number 123. Well, this case is going to be true, right? But it might not be true if phone number part holds different phone numbers. Okay, so let's have this condition now as part of our if statement. We're going to say if open parenthesis, this is the condition close parenthesis, then open the if block with curly braces, then add some mediation to space in my by convention for me. Then you're going to say found phone number with area code 123, something like that. Now, if this condition is true, this will execute. But what if this guy holds different values? So we want to take care of that as well. We're going to use the else block right here, in case this condition turns out to be false. We're going to say that the phone number did not match. Phone number area code did not match something like that. Okay, so we expected to run what because this guy we know, given the value that I set right here, it's going to find 123 for the first element. So it's going to execute this guy and skip the else block. So found phone number area code 123. Now if I change phone number parts to be something else, a new part array of phone number parts, let's say 781 sorry, 781 987 6543, I'm just making these up. So let's say we have now these phone number parts is a different value. Say somehow your program is going through this list of phone number parts, all these phone numbers. And I just change it manually so you can see but the program will do it automatically, but we don't know how to do that yet. But let's just try the RF statement again. So with these values 781 987 6543, we expect our condition right here first you're going to get to this array. Check the first guy is going to be 781 right 781 triple equals 123. That's going to be false because this condition is false. It's going to go to the else block. Everything in the else block will be executed in this case is going to be the console log saying that phone number area code did not match. Let's try it out. There you have it phone number code did not match. All right. So that's it for our exercise in this lesson. And see you next time. Bye.