Java Programming Basics

What is Java?

• Java is a type of dessert

• Java is a type of coffee

• Java is a type of dance

• Java is a high-level, class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible.

What is the main function in Java?

• public static void main(String[] args)

• private void main(String[] args)

• public void main(String[] args)

• static void main(String[] args)

What is the difference between JDK, JRE, and JVM?

• JDK includes JRE and development tools, JRE is used to run Java applications, and JVM is responsible for executing Java bytecode.

• JDK is responsible for executing Java bytecode, JRE is used to run Java applications, and JVM includes development tools.

• JDK is responsible for executing Java bytecode, JRE includes development tools, and JVM is used to run Java applications.

• JDK is used to run Java applications, JRE includes development tools, and JVM is responsible for executing Java bytecode.

What is the use of 'public' keyword in Java?

• It is used to declare a class, method, or field that can only be accessed by a specific instance of the class.

• It is used to declare a class, method, or field that can only be accessed by subclasses.

• It is used to declare a class, method, or field that can be accessed by any other class.

• It is used to declare a class, method, or field that can only be accessed within the same package.

What is the difference between '==' and '.equals()' in Java?

• == compares content, .equals() compares reference

• == and .equals() are used for comparing integers in Java

• == compares reference, .equals() compares content

• == and .equals() are interchangeable in Java

What is the purpose of 'static' keyword in Java?

• To prevent the variable or method from being accessed by any other class

• To make a variable or method accessible only within the same package

• To create a class-level variable or method that can be accessed without creating an instance of the class.

• To allow the variable or method to be overridden by subclasses

What is an interface in Java?

• A reference type similar to a class that is a collection of abstract methods.

• A programming language in Java

• A type of variable in Java

• A built-in function in Java

What is the use of 'this' keyword in Java?

• To refer to the previous instance of the class

• To create a new instance of the class

• To refer to the current instance of the class

• To refer to a different class

What is the difference between 'throw' and 'throws' in Java?

• The main difference is that 'throw' is used to explicitly throw an exception, while 'throws' is used in the method signature to declare that the method may throw an exception.

• The difference is that 'throw' is used for checked exceptions, while 'throws' is used for unchecked exceptions

• In Java, 'throw' is used for handling exceptions within a method, while 'throws' is used for handling exceptions in the calling method

• 'throw' is used for custom exceptions, while 'throws' is used for built-in exceptions

What is the use of 'final' keyword in Java?

• To automatically initialize the variable with a default value

• To allow the user to change the value of a variable anytime

• To make the variable invisible to other classes

• To restrict the user from changing the value of a variable, making it a constant.