In programming, sometimes you need your program to make decisions that have more than just two possible outcomes. Let’s use a movie rating example to understand this better. Imagine you want to determine the highest movie rating someone can watch alone based on their age. The ratings we are considering are R, PG-13, and G.
To handle these different scenarios, we can use an “else if” statement. An “else if” statement is a condition that the program checks only if the previous “if” condition is false. Here’s how it works:
The “else” condition acts as a default. If none of the previous “if” or “else if” conditions are true, the program will follow the “else” statement.
It’s important to be careful with the order of your “if” statements. If you mix up the order, your program might not work as you expect. For example, if you first check if someone is old enough to watch PG-13 movies, then everyone 13 or older will be told they can only watch PG-13 movies, even if they are old enough to watch R-rated movies.
In this case, the program would skip checking if they can watch R-rated movies because the first condition was already true. This happens because the computer checks conditions from top to bottom. Therefore, it’s crucial to put the most specific condition first to ensure the program behaves correctly.
Using “if,” “else if,” and “else” statements allows you to create programs that can make decisions based on multiple conditions. By carefully ordering your conditions, you can ensure your program behaves as intended and provides the correct outcomes for different scenarios.
Imagine you are a movie theater manager. Create a flowchart that shows the decision-making process for allowing people to watch movies based on their age. Use “if,” “else if,” and “else” statements to guide your decisions. Present your flowchart to the class and explain your reasoning.
Write a simple program in your preferred programming language that asks the user for their age and then tells them the highest movie rating they can watch alone. Use “if,” “else if,” and “else” statements to determine the correct output. Share your code with a partner and test each other’s programs.
Experiment with changing the order of conditions in your movie rating program. Predict what will happen if you check for PG-13 before R-rated movies. Run the program to see if your prediction was correct. Discuss with a classmate why the order of conditions is important.
Think of a real-life scenario where multiple conditions are needed to make a decision (e.g., deciding what to wear based on the weather). Write a short script using “if,” “else if,” and “else” statements to handle these conditions. Share your scenario with the class and see if they can identify the conditions you used.
Create an interactive quiz using a platform like Kahoot or Google Forms. Include questions that test your classmates’ understanding of “if,” “else if,” and “else” statements. Make sure to include scenarios where the order of conditions affects the outcome. Host the quiz and discuss the answers with the class.
Here’s a sanitized version of the provided YouTube transcript:
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Sometimes the decisions you want your program to make have more than two possible outcomes. Let’s continue our movie rating example, where we want to check whether the highest rating you can see alone is an R-rated movie, a PG-13 movie, or just a G-rated movie.
To check between these three different cases, we can add an “else if” statement. An “else if” statement is another condition that a program checks only if the previous “if” statements were false.
So, if the age is greater than or equal to 17, the user can see an R-rated movie alone. Else if the age is greater than or equal to 13, the user can see a PG-13 movie alone. Else, the user can see a G-rated movie alone.
The “else” condition becomes the default condition because when all the previous “if” and “else if” statements are false, it will default to the “else” statement.
Be careful as you can construct longer sequences of “if” statements. If you mix up the order, you might not get the behavior you intended. In our example, imagine we had switched the code so that the first condition checked if the user was old enough to see PG-13 movies. This would mean that everyone who is 13 or older would be told they can only see PG-13 movies, even the adults.
With the next “else if” line, the computer would be looking for people 17 or older in the remaining group. This code misses the adults because they were true in that first condition. This won’t work because the computer checks the conditions from top to bottom, so it is important to enter the most specific condition first.
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This version maintains the original meaning while removing any informal language and ensuring clarity.
Programming – The process of creating a set of instructions that tell a computer how to perform a task. – Learning programming can help you create your own computer games.
Conditionals – Statements in programming that only run when certain conditions are true. – In coding, conditionals help the program decide what to do based on user input.
Statements – Instructions written in a programming language that perform a specific action. – Each line of code in your program is made up of statements that tell the computer what to do.
Outcomes – The results produced by executing a program or a specific block of code. – Different inputs can lead to different outcomes in a program.
Decisions – Choices made by a program based on conditions and logic. – The program uses decisions to determine which path to take when running.
Age – A variable often used in programs to determine if a user meets certain criteria, like being old enough to access content. – The program checks the user’s age before allowing access to the website.
Movie – A type of media content that can be managed or accessed through a program. – The app uses a database to store information about each movie.
Ratings – A system used to evaluate or classify content, often used in programs to filter or recommend items. – The program suggests movies based on their ratings and user preferences.
Else – A keyword in programming used to specify an alternative block of code to execute if the condition is false. – If the user is not logged in, the program will execute the else block to redirect them to the login page.
If – A keyword in programming used to specify a block of code that runs only if a certain condition is true. – The program checks if the password is correct before granting access.
