Java Questions & Answers – Relational Operators and Boolean Logic Operators

This section of our 1000+ Java MCQs focuses on relational operators and boolean logic operators of Java Programming Language.

1. What is the output of relational operators?
a) Integer
b) Boolean
c) Characters
d) Double
View Answer

Answer: b
Explanation: None.

2. Which of these is returned by greater than, <, and equal to, ==, operator?
a) Integers
b) Floating - point numbers
c) Boolean
d) None of the mentioned
View Answer

Answer:c
Explanation: All relational operators return a boolean value i:e true and false.

3. Which of the following operators can operate on a boolean variable?
1. &&
2. ==
3. ?:
4. +=
a) 3 & 2
b) 1 & 4
c) 1, 2 & 4
d) 1, 2 & 3
View Answer

Answer: d
Explanation: Operator Short circuit AND, &&, equal to, == , ternary if-then-else, ?:, are boolean logical operators. += is an arithmetic operator it can operate only on numeric values.

4. Which of these operators can skip evaluating right hand operand?
a) !
b) |
c) &
d) &&
View Answer

Answer: d
Explanation: Operator short circuit and, &&, and short circuit or, ||, skip evaluating right hand operand when output can be determined by left operand alone.

5. Which of these statement is correct?
a) true and false are numeric values 1 and 0.
b) true and false are numeric values 0 and 1.
c) true is any non zero value and false is 0.
d) true and false are non numeric values.
View Answer

Answer: d
Explanation: true and false are keywords, they are non numeric values which do no relate to zero or non zero numbers. true and false are boolean values.

6. What is the output of this program?

  1.     class Relational_operator {
  2.         public static void main(String args[])
  3.         {
  4.             int var1 = 5; 
  5.             int var2 = 6;
  6.             System.out.print(var1 > var2);
  7.         } 
  8.     }

a) 1
b) 0
c) true
d) false
View Answer

Answer:d
Explanation: Operator > returns a boolean value. 5 is not greater than 6 therefore false is returned.
output:
$ javac Relational_operator.java
$ java Relational_operator
false

7. What is the output of this program?

  1.     class bool_operator {
  2.         public static void main(String args[]) 
  3.         {    
  4.              boolean a = true;
  5.              boolean b = !true;
  6.              boolean c = a | b;
  7.  	     boolean d = a & b;
  8.              boolean e = d ? b : c;
  9.              System.out.println(d + " " + e);
  10.         } 
  11.     }

a) false false
b) true ture
c) true false
d) false true
View Answer

Answer: d
Explanation: Operator | returns true if any one operand is true, thus ‘c = true | false’ is true. Operator & returns a true if both of the operand is true thus d is false. Ternary operator ?: assigns left of ‘:’ if condition is true and right hand of ‘:’ if condition is false. d is false thus e = d ? b : c , assigns c to e , e contains true.
output:
$ javac bool_operator.java
$ java bool_operator
false true

8. What is the output of this program?

  1.     class ternary_operator {
  2.         public static void main(String args[]) 
  3.         {        
  4.              int x = 3;
  5.              int y = ~ x;
  6.              int z;
  7.              z = x > y ? x : y;
  8.              System.out.print(z);
  9.         } 
  10.     }

a) 0
b) 1
c) 3
d) -4
View Answer

Answer:c
Explanation: None.
output:
$ javac ternary_operator.java
$ java ternary_operator
4

9. What is the output of this program?

  1.     class Output {
  2.         public static void main(String args[]) 
  3.         {    
  4.              int x , y = 1;
  5.              x = 10;
  6.              if (x != 10 && x / 0 == 0)
  7.                  System.out.println(y);
  8.              else
  9.                  System.out.println(++y);
  10.         } 
  11.     }

a) 1
b) 2
c) Runtime error owing to division by zero in if condition.
d) Unpredictable behavior of program.
View Answer

Answer: b
Explanation: Operator short circuit and, &&, skips evaluating right hand operand if left hand operand is false thus division by zero in if condition does not give an error.
output:
$ javac Output.java
$ java Output
2

10. What is the output of this program?

  1.     class Output {
  2.         public static void main(String args[]) 
  3.         {    
  4.              boolean a = true;
  5.              boolean b = false;
  6.              boolean c = a ^ b;
  7.              System.out.println(!b);
  8.         } 
  9.     }

a) 0
b) 1
c) false
d) true
View Answer

Answer: c
Explanation: None.
output:
$ javac Output.java
$ java Output
false

Sanfoundry Global Education & Learning Series – Java Programming Language.

About

Manish Bhojasia, a technology veteran with 17+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer and SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage & Cluster Administration, Advanced C Programming, SAN Storage Technologies, SCSI Internals and Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him below.


Sanfoundry Training Center of Excellence (CoE)

Manish Bhojasia, a technology veteran with 17+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer and SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage & Cluster Administration, Advanced C Programming, SAN Storage Technologies, SCSI Internals and Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him below.







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