Java Multiple Choice Questions & Answers on Assignment Operators and Operator Precedence for Freshers

1. Which of these have highest precedence?

a) ()
b) ++
c) *
d) >>

Answer: a

Explanation: Order of precedence is (highest to lowest) a -> b -> c -> d.

2. What should be expression1 evaluate to in using ternary operator as in this line?
expression1 ? expression2 : expression3

a) Integer
b) Floating – point numbers
c) Boolean
d) None of the mentioned

Answer:c

Explanation: The controlling condition of ternary operator must evaluate to boolean.

3. What is the value stored in x in following lines of code?

int x, y, z;
x = 0;
y = 1;
x = y = z = 8;

a) 0
b) 1
c) 9
d) 8

Answer: d

4. What is the order of precedence (highest to lowest) of following operators?

1. &
2. ^
3. ?:

a) 1 -> 2 -> 3
b) 2 -> 1 -> 3
c) 3 -> 2 -> 1
d) 2 -> 3 -> 1

Answer: a

5. Which of these statements are incorrect?

a) Equal to operator has least precedence.
b) Brackets () have highest precedence.
c) Division operator, /, has higher precedence than multiplication operator.
d) Addition operator, +, and subtraction operator have equal precedence.

Answer: c

Explanation: Division operator, /, has equal precedence as of multiplication operator. In expression involving multiplication and division evaluation of expression will begin from right side when no brackets are used.

6. What is the output of this program?

1.     class operators {

2.         public static void main(String args[])

3.         {

4.             int var1 = 5; 

5.             int var2 = 6;

6.             int var3;

7.             var3 = ++ var2 * var1 / var2 + var2;

8.             System.out.print(var3);

9.         } 

10.     }

a) 10
b) 11
c) 12
d) 56

Answer:c

Explanation: Operator ++ has the highest precedence than / , * and +. var2 is incremented to 7 and then used in expression, var3 = 7 * 5 / 7 + 7, gives 12.

7. What is the output of this program?

1.     class operators {

2.         public static void main(String args[]) 

3.         {    

4.              int x = 8;

5.              System.out.println(++x * 3 + " " + x);

6.         } 

7.     }

a) 24 8
b) 24 9
c) 27 8
d) 27 9

Answer: d

Explanation: Operator ++ has higher precedence than multiplication operator, *, x is incremented to 9 than multiplied with 3 giving 27.

8. What is the output of this program?

1. class Output {

2.         public static void main(String args[]) 

3.         {    

4.              int x=y=z=20;

6.         } 

7.     }

a) compile and runs fine
b) 20
c) run time error
d) compile time error

Answer:d

9. Which of these lines of code will give better performance?

1. a | 4 + c >> b & 7;
2. (a | ((( 4 * c ) >> b ) & 7 ))

a) 1 will give better performance as it has no parentheses.
b) 2 will give better performance as it has parentheses.
c) Both 1 & 2 will give equal performance.
d) Dependent on the computer system.

Answer: c

Explanation: Parentheses do not degrade the performance of the program. Adding parentheses to reduce ambiguity does not negatively affect your system.

10. What is the output of this program?

1. class Output {

2.         public static void main(String args[]) 

3.         {    

4.              int a,b,c,d;

5.              a=b=c=d=20

6.             a+=b-=c*=d/=20

7.         System.out.println(a+" "+b+" "+c+" "+d);

9.          } 

10.     }

a) compile time error
b) runtime error
c) a=20 b=0 c=20 d=1
d) none of the mentioned

Answer: c

Explanation: Expression will evaluate from right to left.