Operators and Expressions - C Programming MCQ Questions and Answers

51

Which operator from the following has the lowest priority?

A) Assignment operator B) Division operator C) Comma operator D) Conditional operator E) Unary-operator

Discuss

Answer & Solution

Answer: Option C

Solution:

C Operator Precedence Table

52

Identify the correct output of the following code:

void main()
{
   int w=10, x=5, y=3, z=3;
   if( (w < x ) && (y=z++) )
      printf("%d %d %d %d", w, x, y, z);
   else
      printf("%d %d %d %d", w, x, y, z);
}

A) 10 5 4 4 B) 10 5 3 3 C) 10 5 4 3 D) 10 5 3 4 E) 10 5 5 5

Discuss

Answer & Solution

Answer: Option B

Solution:

As the first condition ( w < x) is false and the logical operator && is used, the entire relation becomes false and the second part ( y = z++) is not executed.

53

Given b=110 and c=20, what is the value of 'a' after execution of the expression a=b-=c*=5?

A) 450 B) 10 C) 110 D) -10 E) -110

Discuss

Answer & Solution

Answer: Option B

Solution:

As the expression is evaluated from right to left.

54

what will be the output when following code is executed?

void main()
{
   int a=10, b;
   b = a++ + ++a;
   printf("%d %d %d %d", b, a++, a, ++a);
}

A) 12 10 11 13 B) 22 12 12 13 C) 22 11 11 11 D) 22 14 12 13 E) 22 13 14 14

Discuss

Answer & Solution

Answer: Option E

Solution:

Step 1:
Initialize a with the value 10.

Step 2:
Declare b without initialization (the initial value is undefined).

Step 3:
Evaluate a++ (post-increment):
  - The current value of a is 10.
  - After evaluating a++, a becomes 11.

Step 4:
Evaluate ++a (pre-increment):
  - ++a increments a to 12 and returns the updated value, which is 12.

Step 5:
Sum the values obtained in steps 3 and 4: 10 + 12 equals 22.

Step 6:
Assign the sum (22) to b.

Step 7:
The printf function follows the stack Last-In-First-Out (LIFO) concept, which means that the expressions are evaluated from right to left.

Step 8:
The first expression to be evaluated is ++a:
  - ++a increments a to 13 and returns the updated value, which is 13.

Step 9:
The next expression to be evaluated is a++:
  - a++ returns the current value of a (13) and then increments a to 14.
  - The returned value is 13.

Step 10:
Finally, the last expression to be evaluated is a, which has the current value of 14.

Therefore, the output of the program will be:
22 13 14 14

This output corresponds to the value of b, followed by the evaluated values of a++, a, and ++a, respectively, in the printf statement.

55

Which among the following statement is right?

A) sizeof(struct stemp*) > sizeof(union utemp*) > sizeof(char *) B) sizeof(struct stemp*) < sizeof(union utemp*) < sizeof(char *) C) sizeof(struct stemp*) = sizeof(union utemp*) = sizeof(char *) D) the order Depends on the compiler

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Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

56

What will be the output of the following C code?

#include <stdio.h>
int main()
{
    float a = 2.455555555555;
    printf("%f", a);
}

A) 2.455555 B) 2.455556 C) 2.456 D) 2.46

Discuss

Answer & Solution

Answer: Option A

No explanation is given for this question. Let's Discuss on Board

57

Which of the following % operation is invalid?

A) 2 % 4; B) 2 % 4l; C) 2 % 4f; D) Both 2 % 4l; and 2 % 4f;

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Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

58

In the following C code, the union size is decided by?

union temp
{
    char a;
    int b;
    float c;
};

A) char B) int C) float D) both int and float

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Answer & Solution

Answer: Option D

No explanation is given for this question. Let's Discuss on Board

59

Modulus for float could be achieved by?

A) a % b B) modulus(a, b); C) fmod(a, b); D) mod(a, b);

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Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board

60

Which among the following has the highest precedence?

A) & B) << C) sizeof() D) &&

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Answer & Solution

Answer: Option C

No explanation is given for this question. Let's Discuss on Board