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Java Basics

1/25 Which of these is not a valid Java access modifier?
- public
- protected
- private
- friend
2/25 Which method is called when an object is cloned in Java?
- cloneMethod()
- copy()
- clone()
- Object.clone()
3/25 Which Java feature allows the method of a subclass to override the method of its superclass?
- Inheritance
- Encapsulation
- Polymorphism
- Abstraction
4/25 In Java, what does the 'volatile' keyword do to a variable?
- It ensures the variable is synchronized across threads
- It makes the variable immutable
- It increases the variable's access speed
- It makes the variable transient
5/25 Which of the following is true about a 'final' class in Java?
- It can be extended by other classes
- It cannot be instantiated
- It can have final methods only
- It cannot be extended by other classes
6/25 Which of these data types is used to represent a single character in Java?
- String
- char
- Character
- byte
7/25 How do you handle exceptions in Java?
- Using try-catch blocks
- By using the 'throws' keyword
- By using the 'extends' keyword
- By declaring them as static
8/25 What is the function of the 'extends' keyword in Java?
- To inherit methods from an interface
- To extend a method's functionality
- To inherit properties and methods from a superclass
- To extend the memory allocation for an object
9/25 What is the role of the 'import' statement in Java?
- To include a package in the current file
- To export a class to another file
- To load a library at runtime
- To declare a variable
10/25 How is a 'JFrame' used in Java?
- To create a console-based application
- To create a GUI window
- To manage database connections
- To store data in a file
11/25 What is an interface in Java?
- A class that is used to group related methods with empty bodies
- A tool used to debug Java applications
- A type of data structure
- A template for creating objects
12/25 How do you declare a constant variable in Java?
- Using the 'constant' keyword
- Using the 'static final' keywords
- Using the 'immutable' keyword
- Declaring without initialization
13/25 What is the role of the 'break' statement in a loop in Java?
- To skip the current iteration of the loop
- To pause the loop execution temporarily
- To terminate the loop immediately
- To continue loop execution indefinitely
14/25 Which method is used to compare two strings for equality in Java?
- compareTo()
- equals()
- equalsIgnoreCase()
- compare()
15/25 What does the 'final' keyword indicate when applied to a method in Java?
- The method can be overridden in a subclass
- The method cannot be overridden in a subclass
- The method will return a final value
- The method will be executed at the end of the program
16/25 In Java, what is the default layout manager for the JFrame container?
- FlowLayout
- GridLayout
- BorderLayout
- CardLayout
17/25 What is the main difference between a Java class and a Java interface?
- A class defines object properties, an interface defines object behavior
- A class can be instantiated, but an interface cannot
- Interfaces support multiple inheritance, classes do not
- A class is used for implementation, an interface is used for abstraction
18/25 How can you achieve thread safety in Java?
- By using synchronized blocks or methods
- By avoiding the use of multiple threads
- By using the 'volatile' keyword
- By making all methods and variables private
19/25 What is 'JDBC' in Java?
- Java Database Connectivity, a standard API for database access
- Java Data Binding Code, a framework for binding data to UI elements
- Just-in-time Database Compiler, a tool for database optimization
- Java Deployment and Compilation, a deployment tool
20/25 What is 'encapsulation' in Java?
- The technique of wrapping code and data together into a single unit
- A process of linking a method with an object
- A method of improving code execution time
- The division of a program into smaller parts
21/25 How is a 'static inner class' different from a 'non-static inner class' in Java?
- Static inner class can access static members of the outer class only
- Non-static inner class cannot access any members of the outer class
- Static inner class requires an instance of the outer class to exist
- Non-static inner class can exist independently of the outer class
22/25 In Java, what is the purpose of the 'enum' keyword?
- To define a new exception type
- To declare a collection of constants
- To create an enumeration of values for iteration
- To optimize memory usage in large applications
23/25 In Java, which method would you use to compare two String objects for content equality?
- compareTo()
- equals()
- match()
- equalContent()
24/25 What is the advantage of using a 'PreparedStatement' in JDBC?
- Faster execution for repeated queries
- Allows execution of dynamic queries only
- Automatically closes database connections
- Improves the UI of the application
25/25 What does the 'static' keyword signify when applied to a block of code in Java?
- The code block is related to the static members of the class
- The code block cannot be modified
- The code block is executed when the JVM loads the class
- The code block is executed immediately after the class is instantiated
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