Unit 1: Primitive Types - AP Computer Science A

If your code has a syntax error, what kind of error will you see on the console?

• compile-time error

• ArithmeticException

• logic error

• NullPointerException

• IndexOutOfBoundsException

​ (a)   means to tell the computer that you want to use a variable and give it a name.

​ (b)   means to give that variable its first value.

• Declare
• Initialize
• Start
• Create
• Make

The word c_____e means to change source code (like Java) into machine code or bytecode (e.g. 0s and 1s).

You need to create a variable for the number of cars owned. Which variable initialization is best?

• int carsOwned;

• double carsOwned;

• int num_cars;

• double numberOfCarsOwned;

• int numberOfCarsOwned;

Answer explanation

You can't have half a car or 0.5 cars, so we should create an "int" variable.

Good variable names are easy to understand, short, and written in camelCase.

You need to create a variable for the number of computers in the school lab. Which variable initialization is best?

• int computersInLab;

• double computersInLab;

• int num_computers_in_lab;

• double numberOfComputersInLab;

• int numberOfComputersInLab;

Why is it important to choose good variable names when creating variables in Java?

• Good variable names improve code readability and maintainability, making it easier to cooperate with others..

• Good variable names improve code efficiency.
• Good variable names reduce the size of the code.
• Good variable names make the code run faster.

You need to create a variable for the price of a sandwich. Which variable initialization is best?

• int sandwichPrice;

• double sandwichPrice;

• int sandwich_price;

• double priceOfASandwich;

• int priceOfASandwich;

Answer explanation

Prices are usually written in decimal form (e.g. $xx.xx), so it's best to use a "double" variable.

Good variable names are easy to understand, short, and written in camelCase.

What is this symbol called? ;

Which of these variable names is written in camel case?

• myVariable
• my_variable
• MYVARIABLE
• my-variable

Match the following:

• =

• equals sign

• ( )

• forward slash

• /

• semicolon

• %

• modulo

• ;

• parenthesis