Mastering Java Fundamentals

What are the four main data types in Java?

• string, float, byte, short

• int, double, char, boolean

• int, long, float, string

• char, boolean, array, object

What is the difference between int and Integer in Java?

• Integer is faster than int in performance.

• int can hold null values; Integer cannot.

• int is a primitive type; Integer is a wrapper class.

• int is a reference type; Integer is a primitive type.

How do you declare a variable in Java?

• = ;

• To declare a variable in Java, use the syntax: ; = ;

• : ;

• declare ;

What is a control flow statement in Java?

• A control flow statement in Java is used to declare variables.

• A control flow statement in Java is a type of data structure.

• A control flow statement in Java is a method for defining classes.

• A control flow statement in Java directs the execution flow of the program based on conditions.

Explain the use of the if-else statement in Java.

• The if-else statement is a method for creating loops in Java.

• The if-else statement is used for defining classes in Java.

• The if-else statement allows for conditional execution of code based on boolean expressions.

• The if-else statement is a way to declare variables in Java.

What is a switch statement and when would you use it?

• A switch statement is used to execute different code blocks based on the value of a variable or expression.

• A switch statement is a type of conditional that only works with strings.

• A switch statement is used to define functions in programming.

• A switch statement is used for looping through arrays.

What is the purpose of a loop in Java?

• The purpose of a loop in Java is to execute a block of code multiple times based on a condition.

• To create a new class in Java.

• To define a method in Java.

• To store data in a variable.

Describe the difference between for loop and while loop.

• For loop: requires a condition; While loop: does not require any condition.

• For loop: used for conditional checks; While loop: used for counting iterations.

• For loop: known iterations; While loop: unknown iterations until condition fails.

• For loop: executes indefinitely; While loop: executes a fixed number of times.

What is Object-Oriented Programming (OOP)?

• A programming language that only uses functions

• Object-Oriented Programming (OOP) is a programming paradigm that uses 'objects' to design applications.

• A way to create static websites

• A method for writing procedural code

What are the four main principles of OOP?

• Aggregation

• Composition

• Encapsulation, Abstraction, Inheritance, Polymorphism

• Interface