Java Variables MCQ - Multiple Choice Questions And Answers

Q. What is the purpose of a variable in Java?

A. To store and manipulate data
B. To define classes
C. To perform mathematical operations
D. To control program flow

Q. What is the data type of the variable "x" in the following code snippet: int x = 5;

A. int
B. double
C. boolean
D. String

Q. Which of the following is not a valid variable name in Java?

A. myVariable
B. _variable
C. 2variable
D. variable2

Q. What is the default value of an uninitialized int variable in Java?

A. 0
B. null
C. false
D. undefined

Q. Which keyword is used to declare a constant variable in Java?

A. constant
B. final
C. static
D. const

Q. Which of the following is a valid variable declaration in Java?

A. int x;
B. x = 5;
C. var x = 5;
D. All of the above

Q. What is the scope of a local variable in Java?

A. It is accessible throughout the entire program
B. It is accessible within the method or block of code where it is declared
C. It is accessible within the class where it is declared
D. It is accessible within the package where it is declared

Q. What is the difference between instance variables and local variables in Java?

A. Instance variables are declared within a method, while local variables are declared within a class
B. Instance variables are accessible throughout the entire program, while local variables are only accessible within the method or block of code where they are declared
C. Instance variables are declared within a class, while local variables are declared within a method or block of code
D. There is no difference between instance variables and local variables in Java

Q. What is the purpose of the final keyword in Java?

A. To make a variable constant
B. To indicate the end of a program
C. To perform mathematical operations
D. To control program flow

Q. What is the data type of the variable "name" in the following code snippet: String name = "John";

A. int
B. double
C. boolean
D. String

Q. What is the correct way to declare an integer variable in Java?

int x = 5;

Integer x = 5;

Int x = 5;

x = 5;

Q. What will be the value of x after executing the following code snippet?

int x = 10;
x++;
x *= 2;
x -= 5;
x /= 3;

Q. What is the correct syntax to declare a constant variable in Java?

final int MAX_VALUE = 100;

constant int MAX_VALUE = 100;

int MAX_VALUE = 100;
MAX_VALUE.constant();

final MAX_VALUE = 100;

Q. Which of the following statements is true about variable names in Java?

Variable names can contain spaces.

Variable names can start with a number.

Variable names are case-insensitive.

Variable names can include special characters like # and @.

Q. What is the scope of a variable declared inside a method in Java?

Method-local scope

Class scope

Global scope

Object scope

Q. What is the default value of an uninitialized integer variable in Java?

null

NaN

Q. Which of the following is a valid variable name in Java?

variable-name

2variable

_variable

$variable

Q. What is the difference between local variables and instance variables in Java?

Local variables can only be accessed within the method they are declared in, while instance variables can be accessed by any method within the class.

Local variables have a shorter lifespan and are destroyed when the method they are declared in is executed, while instance variables exist as long as the object of the class exists.

Local variables are declared within a method, while instance variables are declared within a class but outside any method.

All of the above.

Q. Which of the following is the correct way to declare a string variable in Java?

string text = "Hello";

String text = "Hello";

String text = Hello;

text = "Hello";

Q. What is the purpose of initializing a variable in Java?

To allocate memory for the variable.

To assign a value to the variable.

To specify the data type of the variable.

To make the variable accessible to other methods.

Search Tutorials