laboursonline – MCQs, Mock Tests | C/C C Multiple Choice Questions C Operators

What is the output of this C code? int main() { int i = -5; int k = i %4; printf("%d ", k); }

1. Compile time error
2. -1
3. 1
4. None

✅ Correct Answer: 2

What is the output of this C code? int main() { int i = 5; int l = i / -4; int k = i % -4; printf("%d %d ", l, k); return 0; }

1. Compile time error
2. -1 1
3. 1 -1
4. Run time error

✅ Correct Answer: 2

What is the output of this C code? int main() { int i = 7; i = i / 4; printf("%d ", i); return 0; }

1. Run time error
2. 1
3. 3
4. Compile time error

✅ Correct Answer: 2

What is the value of x in this C code? void main() { int x = 4 *5 / 2 + 9; }

1. 6.75
2. 1.85
3. 19
4. 3

✅ Correct Answer: 3

What is the output of this C code? void main() { int x = 4.3 % 2; printf("Value of x is %d", x); }

1. Value of x is 1.3
2. Value of x is 2
3. Value of x is 0.3
4. Compile time error

✅ Correct Answer: 4

What is the output of this C code? void main() { int y = 3; int x = 7 % 4 * 3 / 2; printf("Value of x is %d", x); }

1. Value of x is 1
2. Value of x is 2
3. Value of x is 3
4. Compile time error

✅ Correct Answer: 1

What is the output of this C code? void main() { int a = 5; int b = ++a + a++ + --a; printf("Value of b is %d", b); }

1. Value of x is 16
2. Value of x is 21
3. Value of x is 15
4. Undefined behaviour

✅ Correct Answer: 4

The precedence of arithmetic operators is (from highest to lowest)?

1. %, *, /, +, -
2. %, +, /, *, -
3. +, -, %, *, /
4. %, +, -, *, /

✅ Correct Answer: 1

Which of the following is not an arithmetic operation?

1. a *= 20;
2. a /= 30;
3. a %= 40;
4. a != 50;

✅ Correct Answer: 4

Which of the following data type will throw an error on modulus operation(%)?

1. char
2. short
3. float
4. int

✅ Correct Answer: 3

What is the output of this C code? int main() { int a = 20; double b = 15.6; int c; c = a + b; printf("%d", c); }

1. 35
2. 36
3. 35.6
4. 30

✅ Correct Answer: 1

What is the output of this C code? int main() { int a = 20, b = 15, c = 5; int d; d = a == (b + c); printf("%d", d); } A. 1

1. 1
2. 40
3. 10
4. 5

✅ Correct Answer: 1

What is the output of this C code? void main() { int x = 0; if (x = 0) printf("Its zero "); else printf("Its not zero "); }

1. ts not zero
2. Its zero
3. Run time error
4. None

✅ Correct Answer: 1

What is the output of this C code? void main() { int k = 8; int x = 0 == 1 && k++; printf("%d%d ", x, k); }

1. 0 9
2. 0 8
3. 1 9
4. 1 8

✅ Correct Answer: 2

What is the output of this C code? void main() { char a = 'a'; int x = (a % 10)++; printf("%d ", x); }

1. 6
2. Junk value
3. Compile time error
4. 7

✅ Correct Answer: 3

What is the output of this C code? void main() { 1 < 2 ? return 1: return 2; }

1. returns 1
2. returns 2
3. varies
4. Compile time error

✅ Correct Answer: 4

What is the output of this C code? void main() { unsigned int x = -5; printf("%d", x); }

1. Run time error
2. Varies
3. -5
4. 5

✅ Correct Answer: 3

What is the output of this C code? void main() { unsigned int x = -5; printf("%d", x); }

1. Run time error
2. Varies
3. -5
4. 5

✅ Correct Answer: 3

What is the output of this C code? int main() { int x = 2, y = 1; x *= x + y; printf("%d ", x); return 0; }

1. 5
2. 6
3. Undefined behaviour
4. Compile time error

✅ Correct Answer: 4

What is the output of this C code? int main() { int x = 2, y = 2; x /= x / y; printf("%d ", x); return 0; }

1. 2
2. 1
3. 0.5
4. Undefined behaviour

✅ Correct Answer: 1

What is the type of the below assignment expression if x is of type float, y is of type int? y = x + y;

1. int
2. float
3. There is no type for an assignment expression
4. double

✅ Correct Answer: 1

What is the value of the below assignment expression (x = foo())!= 1 considering foo() returns 2

1. 2
2. True
3. 1
4. 0

✅ Correct Answer: 1

Operation "a = a * b + a can also be written as:

1. a *= b + 1
2. (c = a * b)!=(a = c + a)
3. a = (b + 1)* a;
4. All of the mentioned

✅ Correct Answer: 4

for c = 2, value of c after c <<= 1;

1. c = 1;
2. c = 2;
3. c = 3;
4. c = 4;

✅ Correct Answer: 4

What is the output of this C code? int main() { int a = 1, b = 2; a += b -= a; printf("%d %d", a, b); }

1. 1 1
2. 1 2
3. 2 1
4. 2 2

✅ Correct Answer: 3

What is the output of this C code? int main() { int a = 4, n, i, result = 0; scanf("%d", n); for (i = 0;i < n; i++) result += a; }

1. Addition of a and n
2. Subtraction of a and n.
3. Multiplication of a and n
4. Division of a and n.

✅ Correct Answer: 3

Which of the following is an invalid assignment operator?

1. a %= 10;
2. a /= 10
3. a |= 10
4. None of the mentioned

✅ Correct Answer: 4

What is the output of this C code? int main() { int c = 2 ^ 3; printf("%d ", c); }

1. 1
2. 8
3. 9
4. 0

✅ Correct Answer: 1

What is the output of this C code? int main() { unsigned int a = 10; a = ~a; printf("%d ", a); }

1. -9
2. -10
3. -11
4. 10

✅ Correct Answer: 3

What is the output of this C code? int main() { if (7 & 8) printf("Honesty"); if ((~7 & 0x000f) == 8) printf("is the best policy "); }

1. Honesty is the best policy
2. Honesty
3. is the best policy
4. No output

✅ Correct Answer: 3

What is the output of this C code? int main() { int a = 2; if (a >> 1) printf("%d ", a); }

1. 0
2. 1
3. 2
4. No output

✅ Correct Answer: 3

What is the output of this C code? int main() { int a = 2; if (a >> 1) printf("%d ", a); }

1. 0
2. 0
3. 1
4. No output

✅ Correct Answer: 3

Comment on the output of this C code? int main() { int i, n, a = 4; scanf("%d", &n); for (i = 0; i < n; i++) a = a * 2; }

1. Logical Shift left
2. No output
3. Arithmetic Shift right
4. bitwise exclusive OR

✅ Correct Answer: 2

What is the output of this C code? void main() { int x = 97; int y = sizeof(x++); printf("x is %d", x); }

1. x is 97
2. x is 98
3. x is 99
4. Run time error

✅ Correct Answer: 1

What is the output of this C code? void main() { int x = 4, y, z; y = --x; z = x--; printf("%d%d%d", x, y, z); }

1. 3 2 3
2. 2 2 3
3. 3 2 2
4. 2 3 3

✅ Correct Answer: 4

What is the output of this C code? void main() { int x = 4; int *p = &x; int *k = p++; int r = p - k; printf("%d", r); }

1. 4
2. 8
3. 1
4. Run time error

✅ Correct Answer: 3

What is the output of this C code? void main() { int a = 5, b = -7, c = 0, d; d = ++a && ++b || ++c; printf(" %d%d%d%d", a, b, c, d); }

1. 6 -6 0 0
2. 6 -5 0 1
3. -6 -6 0 1
4. 6 -6 0 1

✅ Correct Answer: 4

What is the output of this C code? void main() { int a = -5; int k = (a++, ++a); printf("%d ", k); }

1. -3
2. -5
3. 4
4. Undefined

✅ Correct Answer: 1

What is the output of this C code? int main() { int x = 2; x = x << 1; printf("%d ", x);

1. 4
2. 1
3. Depends on the compiler
4. Depends on the endianness of the machine

✅ Correct Answer: 1

What is the output of this C code? int main() { int x = -2; x = x >> 1; printf("%d ", x); }

1. 1
2. -1
3. 2 ^ 31 "“ 1 considering int to be 4 bytes
4. Either (b) or (c)

✅ Correct Answer: 2

What is the output of this C code? int main() { if (~0 == 1) printf("yes "); else printf("no "); }

1. Yes
2. No
3. Compile time error
4. undefined

✅ Correct Answer: 2

What is the output of this C code? int main() { int x = -2; if (!0 == 1) printf("yes "); else printf("no "); }

1. Yes
2. No
3. Run time error
4. undefined

✅ Correct Answer: 1

What is the output of this C code? int main() { int y = 0; if (1 |(y = 1)) printf("y is %d ", y); else printf("%d ", y); }

1. 1
2. 0
3. Run time error
4. undefined

✅ Correct Answer: 1

What is the output of this C code? int main() { int y = 1; if (y & (y = 2)) printf("true %d "); else printf("false %d "); }

1. true 2
2. false 2
3. Either option a or option b
4. true 1

✅ Correct Answer: 3

What is the difference between the following 2 codes? //Program 1 int main() { int d, a = 1, b = 2; d = a++ + ++b; printf("%d %d %d", d, a, b); } //Program 2 int main() { int d, a = 1, b = 2; d = a++ + ++b; printf("%d %d %d", d, a, b); }

1. No difference as space doesn't make any difference, values of a, b, d are same in both the case
2. No difference as space doesn't make any difference, values of a, b, d are different
3. Program 1 has syntax error, program 2 is not
4. Program 2 has syntax error, program 1 is not

✅ Correct Answer: 1

What is the output of this C code? int main() { int a = 1, b = 1, c; c = a++ + b; printf("%d, %d", a, b); }

1. a = 1, b = 1
2. a = 2, b = 1
3. a = 1, b = 2
4. a = 2, b = 2

✅ Correct Answer: 2

What is the output of this C code? int main() { int a = 1, b = 1, d = 1; printf("%d, %d, %d", ++a + ++a+a++, a++ + ++b, ++d + d++ + a++); }

1. 15, 4, 5
2. 9, 6, 9
3. 9, 3, 5
4. 6, 4, 6

✅ Correct Answer: 1

For which of the following, "PI++; code will fail?

1. #define PI 3.14
2. char *PI = A";
3. float PI = 3.14;
4. Both (A) and (B)

✅ Correct Answer: 1

What is the output of this C code? int main() { int a = 10, b = 10; if (a = 5) b--; printf("%d, %d", a, b--); }

1. a = 10, b = 9
2. a = 10, b = 8
3. a = 5, b = 9
4. a = 5, b = 8

✅ Correct Answer: 3

What is the output of this C code? int main() { int i = 0; int j = i++ + i; printf("%d ", j); }

1. 0
2. 1
3. 2
4. Compile time error

✅ Correct Answer: 1

What is the output of this C code? int main() { int i = 2; int j = ++i + i; printf("%d ", j); }

1. 6
2. 5
3. 4
4. Compile time error

✅ Correct Answer: 1

Comment on the output of this C code? int main() { int i = 2; int i = i++ + i; printf("%d ", i); }

1. = operator is not a sequence point
2. ++ operator may return value with or without side effects
3. it can be evaluated as (i++)+i or i+(++i)
4. Both a and b

✅ Correct Answer: 1

What is the output of this C code? int main() { int i = 0; int x = i++, y = ++i; printf("%d % d ", x, y); return 0; }

1. 0, 2
2. 0, 1
3. 1, 2
4. Undefined

✅ Correct Answer: 1

What is the output of this C code? int main() { int i = 10; int *p = &i; printf("%d ", *p++); }

1. 10
2. 11
3. Garbage value
4. Address of i

✅ Correct Answer: 1

What is the output of this C code? void main() { int x = 97; int y = sizeof(x++); printf("X is %d", x); }

1. X is 97
2. X is 94
3. X is 99
4. Run time error

✅ Correct Answer: 1

What is the output of this C code? void main() { int x = 4, y, z; y = --x; z = x--; printf("%d%d%d", x, y, z); }

1. 3 2 3
2. 2 3 3
3. 3 2 .3
4. 2 3 4

✅ Correct Answer: 2

What is the output of this C code? void main() { int x = 4; int *p = &x; int *k = p++; int r = p - k; printf("%d", r); }

1. 48
2. 8
3. 1
4. Run time error

✅ Correct Answer: 4

What is the output of this C code? void main() { int a = 5, b = -7, c = 0, d; d = ++a && ++b || ++c; printf(" %d%d%d%d", a, b, c, d); }

1. 6 -6 0 0
2. 6 -5 0 1
3. -6 -6 0 1
4. 6 -6 0 1

✅ Correct Answer: 4

What is the output of this C code? void main() { int a = -5; int k = (a++, ++a); printf("%d ", k); } A. -4B. -5C. 4D. -3

1. 4
2. 8
3. 1
4. Run time error

✅ Correct Answer: 4

What is the output of this C code? void main() { int x = 1, y = 0, z = 5; int a = x && y || z++; printf("%d", z); }

1. 6
2. 5
3. 0
4. Varies

✅ Correct Answer: 1

What is the output of this C code? void main() { int x = 1, y = 0, z = 5; int a = x && y && z++; printf("%d", z); }

1. 6
2. 5
3. 0
4. Varies

✅ Correct Answer: 2

What is the output of this C code? int main() { int x = 1, y = 0, z = 3; x > y ? printf("%d", z) : return z; }

1. 3
2. 1
3. Compile time error
4. Run time error

✅ Correct Answer: 3

What is the output of this C code? void main() { int x = 1, z = 3; int y = x << 3; printf(" %d ", y); }

1. -2147483648
2. -1
3. Run time error
4. 8

✅ Correct Answer: 4

What is the output of this C code? void main() { int x = 0, y = 2, z = 3; int a = x & y | z; printf("%d", a); }

1. 3
2. 0
3. 2
4. Run time error

✅ Correct Answer: 1

What is the final value of j in the below code? int main() { int i = 0, j = 0; if (i && (j = i + 10)) //do something ; }

1. 0
2. 10
3. Depends on the compiler
4. Depends on language standard

✅ Correct Answer: 1

What is the output of this C code? int main() { int i = 1; if (i++ && (i == 1)) printf("Yes "); else printf("No "); }

1. Yes
2. No
3. Depends on the compiler
4. Depends on the standard

✅ Correct Answer: 1

Are logical operators sequence points?

1. True
2. False
3. Depends on the compiler
4. Depends on the standard

✅ Correct Answer: 1

Does logical operators in C language are evaluated with short circuit?

1. True
2. False
3. Depends on the compiler
4. depends on the standard

✅ Correct Answer: 1

Result of a logical or relational expression in C is?

1. True or False
2. 0 or 1
3. 0 if expression is false and any positive number if expression is true
4. None of the mentioned

✅ Correct Answer: 2

What will be the value of d in the following program? int main() { int a = 10, b = 5, c = 5; int d; d = b + c == a; printf("%d", d); } A

1. Syntax error
2. 1
3. 5
4. 10

✅ Correct Answer: 2

What is the output of this C code? int main() { int a = 10, b = 5, c = 3; b != !a; c = !!a; printf("%d %d", b, c); }

1. 5 1
2. 0 3
3. 5 3
4. 1 1

✅ Correct Answer: 1

Which among the following is NOT a logical or relational operator? A. !=B. ==C. ||D. = Which among the following is NOT a logical or relational operator?

1. !=
2. ==
3. ||
4. =

✅ Correct Answer: 4

What is the output of this C code? int main() { int a = 10; if (a == a--) printf("TRUE 1 "); a = 10; if (a == --a) printf("TRUE 2 "); }

1. TRUE 1
2. TRUE 2
3. TRUE 1 TRUE 2
4. No output

✅ Correct Answer: 3

Relational operators cannot be used on:

1. structure
2. long
3. strings
4. float

✅ Correct Answer: 1