Lesson 3: Nested if Statements

For the unit project, you will use The Theater to create visualizations of data. Data visualizations help us make sense of data and communicate its story. These visuals are a powerful way to discover and understand these stories and present them to others. Let's take a look at an example.

Discuss: Click through the animated slide to display the prompts.

• What story do you think this data visualization is trying to tell?
• Why do you think the creator chose to visualize the data in this way?

Discussion Goal: Students share opinions and ideas about what they think the data visualization is trying to convey and why the creator chose this visual.

Ask students what other visuals the creator could have used to convey the same story. Have students consider how alternative visuals would have impacted the effectiveness of the message.

In the previous unit, we learned about the term nested when referring to a loop inside another loop. Let's look at how nesting works with if statements.

Do This: Review the lesson objectives.

Group: Place students in pairs.

Do This: Direct students to Level 1 on Code Studio to investigate the program with a partner. Students make the changes to the program as prompted.

Discuss: Click through the animated slide to display the prompts.

• What do you notice about the code in this program?
• What do you wonder about the code in this program?

Discussion Goal: Students notice the nested if statements and that both the outer and inner if statements have to be true for the code to execute. Students may wonder if they can also nest if statements inside the else statement or if there are other ways to check multiple conditions.

Do This: Click through the animated slide to demonstrate a nested if statement and the flowchart for the code segment.

Discuss: Use the Hold That Thought strategy to discuss the prompt.

• Why would we have an if statement in the body of another if statement?

Discussion Goal: Students suggested using nested if statements to allow the program to check conditions within other conditions. Students may share scenarios where they would want to do this, such as checking if someone has enough money for a movie ticket and an available movie time.

If students don’t get to this on their own, ask the following guiding questions:

• What is meant by nested?
• How is this nested statement similar to a nested loop?
• What are some scenarios where you would need to check if multiple conditions were true?

We can use nested if statements to check if multiple conditions are true before executing a block of code. When we are making decisions about how to visualize data, we might choose to display images and shapes based on multiple conditions. Let's see how we can use nested if statements to analyze data and display visuals.

Group: Place students in pairs.

Students can be in the same pairs as the Investigate activity.

Do This: Have students write pseudocode for an algorithm to decide which image to draw based on the given conditions using nested if statements.

Do This: Direct students to Level 2 on Code Studio to complete Levels 2 and 3. Students implement their algorithm on Level 2, then complete a choice level on Level 3 to use nested if statements in different scenarios.

In the previous unit, we worked with data as 1D arrays to answer questions and find information.

Discuss: How might you tell the story behind the data you worked with in the previous unit as a visualization?

Discussion Goal: Students share ideas about how they might visualize the data they worked with in the previous unit, such as displaying shapes in different sizes to correlate with the number of values that meet specific criteria or convey the largest and smallest values in a dataset.

Have students consider how they would create these visualizations in The Theater. Ask students if they would create a static image or an animation and how these approaches would impact the effectiveness of the message.

Do This: Review the concepts covered in this lesson.

Display: Key Vocabulary

Check For Understanding Question(s) and solutions can be found in each lesson on Code Studio. These questions can be used for an exit ticket.

To assign questions from the AP Classroom Question Bank that align with this lesson, create a custom quiz in AP Classroom by searching the Question Bank for the Essential Knowledge statements listed at the top of this lesson plan. You can find instructions and video demonstrations to do this on AP Central.