Java is one of the most popular programming languages in the world. If you’re a beginner, it’s crucial to understand the fundamentals of Java, and variables are a great place to start. Test your knowledge with this Java Variables Quiz consisting of 10 multiple choice questions.
Each question is followed by the correct answer and an explanation to help reinforce your knowledge.
1. Which of the following is a valid variable declaration in Java?
Answer:
Explanation:
In Java, variable names cannot begin with numbers (option a), cannot have single quotes (option c), and type names are case-sensitive, meaning string is incorrect, it should be String (option d).
2. Which data type is used to store a single character in Java?
Answer:
Explanation:
In Java, the char data type is used to store a single character.
3. How many bytes does an int data type occupy in Java?
Answer:
Explanation:
In Java, an int data type occupies 4 bytes.
4. Which of the following is the correct way to declare multiple variables of the same type?
Answer:
Explanation:
All the given options are valid ways to declare multiple variables in Java.
5. Which keyword in Java is used for constant variables?
Answer:
Explanation:
In Java, the final keyword is used to declare constant variables.
6. What will be the default value of an int variable if not initialized in a class?
Answer:
Explanation:
If an int variable is a member of a class and is not initialized, its default value is 0.
7. Which of the following is a valid variable name in Java?
Answer:
Explanation:
Variable names in Java can contain letters, digits, underscores, and dollar signs. They cannot start with a digit or contain Java-reserved words like float.
8. The boolean data type in Java can have values:
Answer:
Explanation:
The boolean data type in Java can only have the values true or false.
9. Which data type can be used to store large decimal numbers in Java?
Answer:
Explanation:
The double data type is used to store large decimal numbers in Java.
10. What is the use of Variables in Java?
Answer:
Explanation:
Variables in Java are containers for storing data values, allowing the program to manipulate or access these values.
11. Which data type is used to store text value in Java?
Answer:
Explanation:
The 'String' data type in Java is used to store text values, which are enclosed in double quotes.
12. What is the purpose of the 'final' keyword in variable declarations in Java?
Answer:
Explanation:
The 'final' keyword in Java is used to declare a variable as constant or unchangeable, making it read-only after its initial assignment.
13. What type of variable in Java is best suited for storing large whole numbers?
Answer:
Explanation:
The 'long' data type in Java is used for storing large whole numbers, which are bigger than what 'int' can store.
14. In Java, what is the default value of a boolean variable?
Answer:
Explanation:
The default value of a boolean variable in Java is 'false' if it is not explicitly initialized.
15. What happens when you assign a new value to an existing variable in Java?
Answer:
Explanation:
When a new value is assigned to an existing variable in Java, the original value is overwritten with the new one.
This quiz should give beginners a basic understanding of Java variables. If you got all the answers correct, well done! If not, don’t worry; practice makes perfect. Keep studying and practicing!