CSAwesome2 AP CSA Java 2025+

This question involves the implementation of a fitness tracking system that is represented by the StepTracker class. A StepTracker object is created with a parameter that defines the minimum number of steps that must be taken for a day to be considered active. The StepTracker class provides a constructor and the following methods.

The following table contains a sample code execution sequence and the corresponding results.

This question asks you to write the complete StepTracker class, including the constructor and any required instance variables and methods. Your implementation must meet all specifications and conform to the example.

Work in pairs or groups to read through the problem statement and determine the instance variables required for this class. During the exam, it helps to mark the words that are important and may describe the instance variables. Different groups may come up with different variables that will still work. Groups should report back and compare answers in class to determine the best variables before writing the class.

It may help to first identify the variables that are needed for the constructor and the accessor and mutator methods.

This question involves the implementation of a fitness tracking system
that is represented by the **StepTracker** class.

A StepTracker object is created with a parameter that defines
the minimum number of steps that must be taken for a day to be active.

The StepTracker class provides a constructor and the following methods.

     - addDailySteps, which accumulates information about steps in readings
       taken once per day.

     - activeDays, which returns the number of active days.

     - averageSteps, which returns the average number of steps per day
       calculated by dividing the total number of steps taken
       by the number of days tracked.

These multiple choice questions will help you to determine the instance variables through the constructor parameters and accessor and mutator methods.

You will receive at least 1 point if you write the class header and a constructor that has the same name as the class and no return type. You will receive another point for creating private instance variables inside the class. Complete the class definition below with the class name, the instance variables you determined above, and the constructor. Remember that for this problem, a StepTracker object is created (with a constructor) with a parameter that defines the minimum number of steps that must be taken for a day to be considered active. The constructor will often have a parameter which it should assign to an instance variable. It should also assign default values to the other instance variables.

Here is the rubric for the instance variables and the constructor for this problem. Did you receive all 3 points? In class, your teacher may have you grade each others’ code.

Each method in the FRQ is worth 1 - 3 points. The method header is usually worth 1 point and the code in the method body is usually worth another point or two depending on how complex it is.

This problem asks you to write a simple accessor method called activeDays which returns the number of active days (which should be an instance variable) for 1 point.

Remember that accessor methods usually look like the following:

class ExampleClass
{
    // Instance variable declaration
    private typeOfVar varName;

    // Accessor method template
    public typeOfVar getVarName()
    {
        return varName;
    }
}

This multiple choice problem can help you determine the accessor method header.

Here is the rubric for the accessor method activeDays for this problem. The second column is small mistakes that will still earn the point but the third column is larger mistakes that will not earn the point. Did you receive the point for this method? In class, your teacher may have you grade each others’ code.

This problem asks you to write a more complex mutator method called addDailySteps worth 3 points.

Remember that mutator methods often look like the following:

class Example
{
    // Instance variable declaration
    private typeOfVar varName;

    // Mutator method template
    public void changeVarName(typeOfVar newValue)
    {
        // an instance variable is changed through = or an operator like +=, -=,
        // ++, etc.
        varName = newValue;
    }
}

This multiple choice problem can help you determine the mutator method header.

The code for this mutator method is a little more complex than the template above, because it needs to change more than 1 instance variable. Notice the comments in the sample code execution:

Consider each of your instance variables and whether this method should change them. The problem below may help you.

Here is the rubric for the mutator method for this problem. The second column is small mistakes that will still earn the point but the third column is larger mistakes that will not earn the point. Did you receive all the points? In class, your teacher may have you grade each others’ code.

This problem asks you to write a more complex accessor method which uses the instance variables to calculate and return the averageSteps for 2 points. This method returns the average number of steps per day, calculated by dividing the total number of steps taken by the number of days tracked.

This multiple choice problem can help you determine the accessor method header.

The complex accessor method averageSteps() must calculate the average number of steps from your instance variables. Notice that the first time it is called in the sample code execution, it returns 0.0 since there are no steps recorded. This avoids a divide by 0 error.

Here is the rubric for the averageSteps method for this problem. Did you receive all the points? In class, your teacher may have you grade each others’ code.