9th pratice
MCQs on Variables
and Data Types
1. What will be the output of the following code?
int a = 5, b = 2;
double c = a / b;
System.out.println(c);
a) 2
b) 2.0
c) 2.5
d) 2.50
✅
Answer: b) 2.0
2. Which of the following is NOT a valid variable
name?
a) _count
b) $total
c) 2value
d) value2
✅
Answer: c) 2value
3. The range of a byte data type in Java is:
a) -128 to 127
b) 0 to 255
c) -255 to 255
d) -127 to 127
✅
Answer: a) -128 to 127
4. What is the output of the following code?
char ch = 'A' + 1;
System.out.println(ch);
a) A
b) B
c) 66
d) Error
✅
Answer: b) B
5. What is the result of 10 + 20 + "Java"?
a) Java30
b) 30Java
c) 1020Java
d) Error
✅
Answer: b) 30Java
6. Which of the following statements is valid?
a) float f = 7.3;
b) float f = 7.3f;
c) float f = "7.3";
d) float f = (float)"7.3";
✅
Answer: b) float f = 7.3f;
7. What is the default value of a local variable in
Java?
a) 0
b) null
c) false
d) No default value
✅
Answer: d) No default value
8. Which of the following is a reference data type?
a) int
b) float
c) char
d) String
✅
Answer: d) String
9. What will be the output?
System.out.println(5 + 5 + "5" + 5 + 5);
a) 55555
b) 10555
c) 105510
d) 10555
✅
Answer: d) 10555
10. Which of the following statements is true?
a) A boolean can store 0 or 1
b) A boolean can store only true or false
c) A boolean can store any number
d) None of the above
✅
Answer: b) A boolean can store only true or false
11. What is the size of a long variable in Java?
a) 2 bytes
b) 4 bytes
c) 8 bytes
d) 16 bytes
✅
Answer: c) 8 bytes
12. What will be the output?
int x = 5;
int y = ++x + x++;
System.out.println(y);
a) 10
b) 11
c) 12
d) 13
✅
Answer: d) 13
13. Which of the following literals represents a
character?
a) 'A'
b) "A"
c) A
d) 'A"
✅
Answer: a) 'A'
14. What is the output?
double a = 10 / 4;
System.out.println(a);
a) 2
b) 2.0
c) 2.5
d) 2.50
✅
Answer: b) 2.0
15. Which of the following
conversions is not allowed automatically (implicit casting)?
a) int → long
b) char → int
c) double → float
d) byte → int
✅ Answer: c) double →
float
16. What is the data type of the result in:
25 / 4.0
a) int
b) float
c) double
d) long
✅
Answer: c) double
17. Which variable declaration is valid?
a) int class = 10;
b) float _price = 12.5f;
c) boolean 1flag = true;
d) char "ch" = 'A';
✅
Answer: b) float _price = 12.5f;
18. What is the output?
char ch = '9';
int n = ch - '0';
System.out.println(n);
a) 9
b) 0
c) 57
d) Error
✅
Answer: a) 9
19. Which of these can store a decimal value?
a) int
b) long
c) float
d) char
✅
Answer: c) float
20. What is the data type of the following literal?
12.34
a) float
b) double
c) long
d) int
✅
Answer: b) double
✍️ 2-Mark Definition Questions
1. Define a variable in Java.
Answer:
A variable in Java is a named memory location used to store data that can
change during program execution.
2. Define a data type in Java.
Answer:
A data type defines the kind of data a variable can hold, such as integer,
floating-point number, character, or boolean.
3. What is meant by implicit type conversion?
Answer:
Implicit type conversion, also called type promotion, occurs when Java
automatically converts a smaller data type into a larger one during an
operation (e.g., int → double).
4. What is explicit type casting?
Answer:
Explicit type casting means manually converting one data type into another
using a cast operator, for example:
double x = (double)5/2;
5. Define identifier with an example.
Answer:
An identifier is the name used to identify a variable, class, or method in
Java.
Example: int marks; — here marks is an identifier.
6. Define literal in Java.
Answer:
A literal is a fixed value that does not change during program execution, such
as 10, 'A', "Hello", or true.
7. What is a constant in Java?
Answer:
A constant is a variable whose value cannot be changed once assigned, declared
using the keyword final.
Example: final int MAX = 100;
8. Define primitive data types in Java.
Answer:
Primitive data types are the basic data types provided by Java for storing
simple values. They are: byte, short, int, long, float, double, char, and
boolean.
9. What is the difference between integer division
and floating-point division?
Answer:
- Integer
division: Both operands are integers; the result is an integer (e.g., 5
/ 2 = 2).
- Floating-point
division: At least one operand is float/double; the result includes a
fraction (e.g., 5.0 / 2 = 2.5).
10. Define type casting and give an example.
Answer:
Type casting is the process of converting a variable from one data type to
another.
Example:
int x = (int) 5.8; // x becomes 5
💻 Hard Programmatic
Question
Question:
Predict the output of the following Java program and explain how
it works.
public class TestDataType {
public static void
main(String[] args) {
int a = 5;
double b = 2.5;
char c = 'A';
int result = (int)(a
+ b) + c;
double finalValue
= (result / 3) + (a % 2) * 1.5;
System.out.println("Result = " + result);
System.out.println("Final Value = " + finalValue);
}
}
Write a Java program to read three numbers and display the largest
number only if the difference between the largest and smallest
number is even, otherwise display their average (as a decimal).
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