laboursonline – MCQs, Mock Tests | C/C C Multiple Choice Questions C Functions Set 1

What is the output of this C code? int main() { void foo(), f(); f(); } void foo() { printf("2 "); } void f() { printf("1 "); foo(); }

1. Compile time error as foo is local to main
2. 1 2
3. 2 1
4. Compile time error due to declaration of functions inside main

✅ Correct Answer: 2

What is the output of this C code? int main() { void foo(); void f() { foo(); } f(); } void foo() { printf("2 "); }

1. 2 2
2. 2
3. Compile time error
4. Depends on the compiler

✅ Correct Answer: 4

What is the output of this C code? void foo(); int main() { void foo(); foo(); return 0; } void foo() { printf("2 "); }

1. Compile time error
2. 2
3. Depends on the compiler
4. Depends on the standard

✅ Correct Answer: 2

What is the output of this C code? void foo(); int main() { void foo(int); foo(1); return 0; } void foo(int i) { printf("2 "); }

1. 2
2. Compile time error
3. Depends on the compiler
4. Depends on the standard

✅ Correct Answer: 1

What is the output of this C code? void m() { printf("hi"); } void main() { m(); }

1. hi
2. Run time error
3. Nothing
4. Varies

✅ Correct Answer: 1

What is the output of this C code? void m() { printf("hi"); } void main() { m(); }

1. hi
2. Run time error
3. Nothing
4. Varies

✅ Correct Answer: 1

What is the output of this C code? void m(); void n() { m(); } void main() { void m() { printf("hi"); } }

1. hi
2. Compile time error
3. Nothing
4. Varies

✅ Correct Answer: 2

What is the output of this C code? void main() { m(); void m() { printf("hi"); } }

1. hi
2. Compile time error
3. Nothing
4. Varies

✅ Correct Answer: 2

What is the output of this C code? void main() { m(); } void m() { printf("hi"); m(); }

1. Compile time error
2. hi
3. Infinite hi
4. Nothing

✅ Correct Answer: 3

What is the output of this C code? void main() { static int x = 3; x++; if (x <= 5) { printf("hi"); main(); } }

1. Run time error
2. hi
3. infinite hi
4. hi hi

✅ Correct Answer: 4

Which of the following function declaration is illegal?

1. int 1bhk(int);
2. int 1bhk(int a);
3. int 2bhk(int*, int []);
4. All of the mentioned

✅ Correct Answer: 4

Which function definition will run correctly?

1. int sum(int a, int b) return (a + b);
2. int sum(int a, int b) {return (a + b);}
3. int sum(a, b) return (a + b);
4. Both (a) and (b)

✅ Correct Answer: 2

Can we use a function as a parameter of another function? [ Eg: void wow(int func()) ]

1. Yes, and we can use the function value conveniently
2. Yes, but we call the function again to get the value, not as convenient as in using variable
3. No, C does not support it
4. This case is compiler dependent

✅ Correct Answer: 3

The value obtained in the function is given back to main by using ________ keyword?

1. return
2. static
3. new
4. volatile

✅ Correct Answer: 1

What is the return-type of the function sqrt()

1. int
2. float
3. double
4. Depends on the data type of the parameter

✅ Correct Answer: 3

Which of the following function declaration is illegal?

1. double func(); int main(){} double func(){}
2. double func(){}; int main(){}
3. int main() { double func(); } double func(){//statements}
4. None of the mentioned

✅ Correct Answer: 4

What is the output of this code having void return-type function? void foo() { return 1; } void main() { int x = 0; x = foo(); printf("%d", x); }

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

✅ Correct Answer: 4

What will be the data type returned for the following function? int func() { return (double)(char)5.0; }

1. char
2. int
3. double
4. multiple type-casting in return is illegal

✅ Correct Answer: 2

What is the problem in the following declarations? int func(int); double func(int); int func(float);

1. A function with same name cannot have different signatures
2. A function with same name cannot have different return types
3. A function with same name cannot have different number of parameters
4. All of the mentioned

✅ Correct Answer: 4

The output of the code below is void main() { int k = m(); printf("%d", k); } void m() { printf("hello"); }

1. hello5
2. Error
3. Nothing
4. Junk value

✅ Correct Answer: 1

The output of the code below is int *m() { int *p = 5; return p; } void main() { int *k = m(); printf("%d", k); }

1. 1
2. Junk value
3. 0
4. 5

✅ Correct Answer: 4

The output of the code below is int *m(); void main() { int *k = m(); printf("hello "); printf("%d", k[0]); } int *m() { int a[2] = {5, 8}; return a; }

1. hello 5 8
2. hello 5
3. hello followed by garbage value
4. Compilation error

✅ Correct Answer: 3

The output of the code below is int *m(); void main() { int k = m(); printf("%d", k); } int *m() { int a[2] = {5, 8}; return a; }

1. 5
2. 8
3. Nothing
4. Varies

✅ Correct Answer: 4

The output of the code below is void m(int k) { printf("hi"); } void m(double k) { printf("hello"); } void main() { m(3); }

1. hi
2. hello
3. hi
4. Nothing

✅ Correct Answer: 3

What is the default return type if it is not specified in function definition?

1. void
2. int
3. double
4. short int

✅ Correct Answer: 2

What is the output of this C code? int foo(); int main() { int i = foo(); } foo() { printf("2 "); return 2; }

1. 1
2. Compile time error
3. Depends on the compiler
4. Depends on the standard

✅ Correct Answer: 1

What is the output of this C code? double foo(); int main() { foo(); return 0; } foo() { printf("2 "); return 2; }

1. 2
2. Compile time error
3. Depends on the compiler
4. Depends on the standard

✅ Correct Answer: 2

functions can return structure in c?

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

✅ Correct Answer: 1

functions can return enumeration constants in c?

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

✅ Correct Answer: 1

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

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

✅ Correct Answer: 2

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

1. Junk value
2. Run time error
3. 0
4. Undefined

✅ Correct Answer: 3

What is the output of this C code? int x = 5; void main() { int x = 3; printf("%d", x); { x = 4; } printf("%d", x); }

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

✅ Correct Answer: 4

What is the output of this C code? int x = 5; void main() { int x = 3; printf("%d", x); { int x = 4; } printf("%d", x); }

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

✅ Correct Answer: 1

Functions in C are ALWAYS:

1. Internal
2. External
3. Both Internal and External
4. External and Internal are not valid terms for functions

✅ Correct Answer: 2

Which of the following are an external variable? int func (int a) { int b; return b; } int main() { int c; func (c); } int d;

1. a
2. b
3. c
4. d

✅ Correct Answer: 4

What will be the output? int main() { printf("%d", d++); } int d = 10;

1. 9
2. 10
3. 11
4. Compile time error

✅ Correct Answer: 4

What will be the output? double var = 8; int main() { int var = 5; printf("%d", var); }

1. 5
2. 8
3. Compile time error due to wrong format identifier for double
4. ompile time error due to redeclaration of variable with same name

✅ Correct Answer: 1

What is the output of this C code? double i; int main() { printf("%g ",i); return 0; }

1. 0
2. 0.000000
3. Garbage value
4. Depends on the compiler

✅ Correct Answer: 2

Which part of the program address space is p stored in the code given below? int *p; int main() { int i = 0; p = &i; return 0; }

1. Code/text segment
2. Data segment
3. Bss segment
4. Stack

✅ Correct Answer: 3

Can variable i be accessed by functions in another source file? int i; int main() { printf("%d ", i); }

1. 0
2. false
3. Only if static keyword is used
4. Depends on the type of the variable

✅ Correct Answer: 1

Property of external variable to be accessed by any source file is called by C90 standard as:

1. external linkage
2. external scope
3. global scope
4. global linkage

✅ Correct Answer: 1

What is the output of this C code? int *i; int main() { if (i == NULL) printf("true "); return 0; }

1. true
2. true only if NULL value is 0
3. Compile time error
4. Nothing

✅ Correct Answer: 1

What is the output of this C code? int *i; int main() { if (i == 0) printf("true "); return 0; }

1. true
2. true only if NULL value is 0
3. Compile time error
4. Nothing

✅ Correct Answer: 2

What is the output of this C code? static int x = 5; void main() { x = 9; { int x = 4; } printf("%d", x); }

1. 9
2. 4
3. 5
4. 0

✅ Correct Answer: 1

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

1. 6 7
2. 6 6
3. 5 5
4. 5 6

✅ Correct Answer: 1

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

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

✅ Correct Answer: 1

What is the output of this C code? static int x; void main() { int x; printf("x is %d", x);

1. 0
2. Junk value
3. Run time error
4. Nothing

✅ Correct Answer: 2

What is the output of this C code? void main() { static double x; int x; printf("x is %d", x); }

1. 0
2. Nothing
3. Compile time error
4. Junk value

✅ Correct Answer: 3

What is the output of this C code? void main() { static int x; if (x++ < 2) main(); }

1. Infinite calls to main
2. Run time error
3. Varie
4. main is called twice

✅ Correct Answer: 4

Which of following is not accepted in C?

1. static a = 10; //static as
2. static int func (int); //parameter as static
3. static static int a; //a static variable prefixed with static
4. All of the mentioned

✅ Correct Answer: 3

Which of the following cannot be static in C?

1. Variables
2. Functions
3. Structures
4. None of the mentioned

✅ Correct Answer: 4

The scope of an automatic variable is:

1. Within the block it appears
2. Within the blocks of the block it appears
3. Until the end of program
4. Both (a) and (b)

✅ Correct Answer: 4

Automatic variables are allocated space in the form of a:

1. stack
2. queue
3. priority
4. random

✅ Correct Answer: 1

Which of the following is a storage specifier?

1. enum
2. union
3. auto
4. volatile

✅ Correct Answer: 3

Default storage class if not any is specified for a local variable, is auto:

1. true
2. false
3. Depends on the standard
4. None of the mentioned

✅ Correct Answer: 1

Automatic variables are stored in:

1. stack
2. data segment
3. register
4. heap

✅ Correct Answer: 1

What linkage does automatic variables have?

1. Internal linkage
2. External linkage
3. No linkage
4. None of the mentioned

✅ Correct Answer: 3

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

1. 10
2. Compile time error
3. Depends on the standard
4. Depends on the compiler

✅ Correct Answer: 1