Mastering Java Keywords

What are the four access modifiers in Java?

• static, final, synchronized, transient

• public, private, static, volatile

• public, private, protected, default

• private, protected, synchronized, transient

Explain the difference between public and private access modifiers.

• Public members can only be accessed within the class and its subclasses.

• Public members are hidden from other classes and can only be accessed by the class itself.

• Public members are accessible from anywhere, while private members are only accessible within the class they are declared.

• Private members are accessible from anywhere in the program.

What is the purpose of the protected access modifier?

• To make class members accessible only to the package they belong to.

• To allow access to class members from any other class.

• To restrict access to class members to the class itself and its subclasses.

• To enable access to class members from any subclass regardless of the package.

How do you create a for loop in Java?

• for(int i = 0; i < 10; i++) { print(i); }

• for(int i = 0; i < 10; i++) { System.out.println(i); }

• for(i = 0; i < 10; i++) { System.out.println(i); }

• for(int i = 0; i < 10; i++) System.out.println(i);

What is the syntax for a while loop in Java?

• while (condition) { // code to be executed }

• while (condition) { code to be executed }

• while (condition) // code to be executed }

• while { condition } // code to be executed

Describe the do-while loop and its use case.

• The do-while loop is used when the code needs to be executed at least once, regardless of whether the condition is true or false.

• The do-while loop executes only if the condition is true.

• The do-while loop is used for iterating over arrays.

• The do-while loop cannot execute any code if the condition is false.

What is the main purpose of a class in Java?

• To execute code directly without a main method.

• To store data in a static format only.

• To manage memory allocation for primitive types.

• The main purpose of a class in Java is to define a blueprint for creating objects.

How do you define a method in a Java class?

• returnType methodName(parameters)

• public returnType methodName(parameters) { // method body }

• public methodName { // method body }

• methodName(parameters) { // method body }

What is the difference between a class and an object?

• A class is a function; an object is a variable.

• A class is a method; an object is a property.

• A class is a type of object; an object is a specific class.

• A class is a blueprint; an object is an instance of that blueprint.

What is a Java package and why is it used?

• A Java package is a tool for debugging Java applications.

• A Java package is a namespace for organizing related classes and interfaces, used to avoid name conflicts and enhance code organization.

• A Java package is a method for encrypting code.

• A Java package is a type of database for storing data.