Hi, everyone in this video clip. Let me introduce two more cases of using "if clauses". The first one is combining conditional statements. In this case, we are taking two numbers by asking two numbers to be type in. Then, the number is transformed into integers here. And those two integers numbers are assigned to weight and height variables. Then, if-clause is following, if weight is greater than or equal to "90" and height is less than or equal to "150". A sentence, would it be printed? So, "and" using "and", we can combine two conditional statements. Surely, we can combine two conditional statements with "or" instead of "and" if you use "and" two conditions simultaneously satisfied, they must be satisfied together. Otherwise, print following printer statement. It's not printed, but if you use "or" statement, either one of the two conditions are met, the print function will work. Surely, you can add another "or" and add one more conditional statement. It doesn't have to be two. This is a very simple case. Then "else" the statement follows two sentences are printed in this case, so "thin" and "eat more". So what about we execute? Like 80 kilogram and 150 centimeters, then "normal" because it belongs to the second. Then what about the other case? Like 45 and 150 ,"thin" "eat more", the last. Two printed sentences are displayed. Now, one question here is that, can we use one print function instead of the two? In order to present "thin" and "eat more". So now, in this example, we are learning how to print two linew with one print command. So how can we do that? Make this dormant, and then it belongs to up like "eat more!" then execute. [typing] 40, 150, then "thin" "eat more" one sentence, but they are in the same line. How can we make the one line into two lines? We are adding "\n" it is. We are inserting your line. After "\n" there is a string, that string will be printed in the following line. So, let us execute this one, like [typing] 45, 150. Then "thin" "eat more", so using this print, print sentence, we can write two, two sentences. So, we don't have to use another print function here. So, using just one, one print command, you can print two lines by using "\n". This is a kind of a trick or a way of simplifying the coding process. Now, let's just studying nested if statement. Nested if statement means that if a statement exists inside of an if statement. So far, when we use multiple if statement, they are separately existing right? But in this case one if statement is indented. It means that it belongs to right above if statement. When do we use this kind of nested if statement, it is used, so a condition is met, but even though a condition is met, you want to subdivide. That group into another two groups. In that case, we use a nested if statement. Let me give you an example, classified beverages, like if you are facing or vending machine in order purchase a beverage, you often need to type in numbers. So it is asking, menus choose a code for ordering a drink then another line comes "10 : Coffee", "20 : Orange Juice", right then asking type a code 10 or 20. Then the number is assigned to "menu" variable. Then if menu is 10, it means that the customer is ordering coffee. If this condition is met, then another question is raise to the Customers, "type 11 for Hot Coffee or 12 for Ice Coffee", then customer will choose one out of the two. So, and that number is assigned to "menu1", if menu1, number is 11 "Here is a cup of hot coffee". If it's value is 12 then another sentence is printed, and if what if the customer presses the wrong number like a 14 or 15 or other numbers rather than 11 or 12 then "A wrong number is chosen! Try again!" And elif comes next, but it is matching with the original if statement first level if statement. So when customers, first type 20 in that case, it comes to here because the first if a command is not satisfied, it means that the whole block is skipped. And "Here's a couple of oranges juice" because customer chosen orange juice. But what about in this case also the customer press, a button other than 10 or 20, then "A wrong number is chosen! Try again" this sentence will be printed. So let's execute this one, then what about 10, choosing coffee, then again, another message comes up 11 or 12 [typing] 11 then "here's a cup of hot coffee" the machine is working perfectly. And what about the other case? [typing] 10, but we use a wrong number, like 26, then "A wrong number is chosen! Try again". So, but this code is working perfectly, but what about you are not using else statement here, making the line dormant and then execute 10 and like 15 wrong number, then nothing happens. Because elif, two following conditions. This condition has not met another condition is not satisfied. It means that there's no action. Nothing happens. So in order to avoid this kind of empty or no response. We need to use, we need to add this final else statement by using else the whole set is completely covered 11, 12, or the other cases. They are all subsumed in else statement. Before closing again this video clip let me give you a review question? What are these "\" and "\n" for? Oh, it means that I didn't explain the "\" here. Here "\" is use, what is the function of this one? Backslash it is used in print statement. If it is used in print statement in means that it is simply continuation of "Choose a code for ordering a drink". If you are not using backslash "a drink" should come, move one step above. So by even though "a drink" appears here in the third line, actually it, when it is printed, "choose a code for ordering a drink" a whole sentence is printed continuously without breaking. So "\" is used to simply let computer know the following line is continued to the first line and here's "\n" it means that line change, new line appears and then the following sentence is printed. And here's another "\n" means that a blank line is added. So it looks like this one. So, what are these "\" and "\n" the first one simple "\" is a continuation sign. "\n" as I said before, it is adding or starting new line after that "\n".
