1.1.2 Variables worksheet

Which statement would you add to display the two other variables that have been declared and initialized?

• print(variable1, variable2)

• display(variable1, variable2)

• show(variable1, variable2)

• log(variable1, variable2)

Answer explanation

The correct choice is 'print(variable1, variable2)' because 'print' is a standard function in many programming languages to output values to the console. The other options do not represent standard output functions.

What is a primitive data type that stores whole numbers?

• A) int

• B) boolean

• C) double

Answer explanation

The correct choice is A) int, which is a primitive data type used to store whole numbers. Options B) boolean and C) double represent different data types: boolean for true/false values and double for floating-point numbers.

Fill in the blank: A _______ variable is stored in a specific memory location and only stores decimal values.

• double

• integer

• character

• boolean

Answer explanation

A double variable is specifically designed to store decimal values and is allocated a specific memory location for this purpose. In contrast, integer, character, and boolean types do not store decimal values.

What is the naming convention used in Java for methods and variables when using two words in a variable name?

Answer explanation

In Java, the naming convention for methods and variables using two words is camelCase. The first word is in lowercase, and the subsequent words start with an uppercase letter, e.g., 'myVariable' or 'calculateTotal'.

Which of the following are rules for naming variables in Java?

• Variable names must start with a letter, underscore, or dollar sign.

• Variable names can contain spaces.

• Variable names are case-sensitive.

• Variable names can start with a number.

Answer explanation

In Java, variable names must start with a letter, underscore, or dollar sign. They cannot contain spaces, are case-sensitive, and cannot start with a number. Thus, the correct rule is that variable names must start with a letter, underscore, or dollar sign.

What is the purpose of declaring a variable as 'final' in programming?

• To allow the variable to be modified later

• To prevent the variable from being modified

• To make the variable accessible globally

• To enhance the performance of the program

Answer explanation

Declaring a variable as 'final' prevents it from being modified after its initial assignment. This ensures that the value remains constant throughout its scope, which can help avoid unintended changes and improve code reliability.

Which of the following is an example of a 'final' variable?

• int age = 12;

• final double ALLOWANCE = 8.75;

• age = 13;

• int speed = 60;

Answer explanation

The correct choice is 'final double ALLOWANCE = 8.75;' because 'final' indicates that the variable's value cannot be changed after it is initialized, making it a constant. The other options do not use 'final'.

Which of the following is NOT a 'final' variable?

• final double PI = 3.1415926;

• final double GOLDEN_RATIO = 1.6180339;

• final int SPEED_OF_LIGHT = 299792458;

• int age = 12;

Answer explanation

The variable 'int age = 12;' is not declared as 'final', meaning its value can be changed. In contrast, the other variables are declared as 'final', making them constants that cannot be modified.

Which of the following is an example of a reference variable declaration?

• int count;

• String name;

• float gpa;

• char firstInitial;

Answer explanation

A reference variable in Java holds a reference to an object. 'String name;' is a reference type, while the others (int, float, char) are primitive types. Therefore, 'String name;' is the correct example of a reference variable declaration.

Which of the following is the correct way to declare a variable?

• variable myName

• var myName

• MY_NAME

• VAR myName

Answer explanation

The correct way to declare a variable in many programming languages is using 'var myName'. The other options are either incorrect syntax or do not follow the conventions for variable declaration.