int main(void)
{
int a=5;
float b;
printf("%d",sizeof(++a+b));
printf("
%d",a);
return 0;
return 0;
}
b) 4 6
c) 2 5
d) 4 5
e) Compiler
error
Output: d)
Explanation:
++a +b
=6 + Garbage floating point
number
=Garbage floating point
number
//From the rule of automatic
type conversion
Hence sizeof operator will
return 4 because size of float data type in c is 4 byte.
Value of any variable doesn’t
modify inside sizeof operator. Hence value of variable a will remain 5.
Read:
Properties of sizeof operator.
Operators tutorial
2. What will be output if you
will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
char *str;
scanf("%[^\n]",str);
printf("%s",str);
return 0;
return 0;
}
a) It will accept a word as a string from user.
b) It will accept a sentence as a string from user.
c) It will accept a paragraph as a string from user.
d) Compiler error
e) None of
above
Output: b)
Explanation:
Task of % [^\t] is to take
the stream of characters until it doesn’t receive new line character ‘\t’ i.e.
enter button of your keyboard.
Read:
General meaning of %[^ p]
String tutorial.
3. What will be output if you
will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
int array[3]={5};
int i;
for(i=0;i<=2;i++)
printf("%d
",array[i]);
return 0;
return 0;
}
a) 5 garbage garbage
b) 5 0 0
c) 5 null null
d) Compiler error
e) None of
above
Output: b)
Explanation:
Storage class of an array
which initializes the element of the array at the time of declaration is
static. Default initial value of static integer is zero.
Read:
Properties of static storage
class.
How to read complex array.
4. What will be output if you will compile and execute the following c code?
#include<stdio.h>
void call(int, int, int);
int main(void)
{
int a=10;
call(a,a++,++a);
return 0;
return 0;
}
void call(int x, int y, int z)
{
printf("%d %d
%d",x,y,z);
}
a) 10 10 12
b) 12 11 11
d) 10 11 12
e) Compiler
error
Output: b)
Explanation:
Default parameter passing
scheme of c is cdecl i.e. argument of function will pass from right to left
direction.
First ++a will pass and a=11
Then a++ will pass and a=11
Then a will pass and a=12
Read:
What is pascal and cedecl parameter passing scheme?
Concept of
variable numbers of argument.
5. What will be output if you will compile and execute the following c code?
#include<stdio.h>
5. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
int x=5,y=10,z=15;
printf("%d %d
%d");
return 0;
return 0;
}
a) Garbage Garbage Garbage
b) 5 10 15
c) 15 10 5
d) Compiler error
e) Run time
error
Output: c)
Explanation:
Auto variables are stored in
stack as shown in following figure.
Stack follow LIFO data
structure i.e. last come and first out. First %d will print then content of two
continuous bytes from the top of the stack and so on.
Read:
Memory map tutorial.
More questions based on memory map.
int main(void)
{
register int i,x;
scanf("%d",&i);
x=++i
+ ++i + ++i;
printf("%d",x);
return 0;
return 0;
}
a) 17
b) 18
c) 21
d) 22
e) Compiler
error
Output: e)
Explanation:
In c register variable stores
in CPU it doesn’t store in RAM. So register variable have not any memory
address. So it is illegal to write &a.
Read:
Complete tutorial of storage
class with examples.
Properties of register storage class.
7. What will be output if you will compile and execute the following c code?
#include<stdio.h>
7. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
int a=5;
int b=10;
{
int a=2;
a++;
b++;
}
printf("%d
%d",a,b);
return 0;
return 0;
}
a) 5 10
b) 6 11
c) 5 11
d) 6 10
e) Compiler
error
Output: c)
Explanation:
Default storage class of
local variable is auto. Scope and visibility of auto variable is within the
block in which it has declared. In c, if there are two variables of the same
name then we can access only local variable. Hence inside the inner block
variable a is local variable which has declared and defined inside that block.
When control comes out of the inner block local variable a became dead.
Read:
Complete tutorial of storage
class with examples.
What is
auto storage class?
8. What will be output if you will compile and execute the following c code?
#include<stdio.h>
8. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
float f=3.4e39;
printf("%f",f);
return 0;
return 0;
}
a) 3.4e39
b) 3.40000…
c) +INF
d) Compiler error
e) Run time
error
Output: c)
Explanation:
If you will assign value
beyond the range of float data type to the float variable it will not show any
compiler error. It will store infinity.
Read:
Data type tutorial with
examples.
Concept of float data type.
9. What will be output if you will compile and execute the following c code?
#include<stdio.h>
9. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
enum color{
RED,GREEN=-20,BLUE,YELLOW
};
enum color x;
x=YELLOW;
printf("%d",x);
return 0;
return 0;
}
a) -22
b) -18
c) 1
d) Compiler error
e) None of
above
Output: b)
Explanation:
Default value of enum
constant = value of previous enum constant +1
Default value of first enum
constant=0
Hence:
BLUE=GREEN+1=-20+1=-19
YELLOW=BLUE+1=-19+1=-18
Read:
Complete tutorial of enum
data type with examples.
10. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
asm{
mov bx,8;
mov cx,10
add bx,cx;
}
printf("%d",_BX);
return 0;
return 0;
}
a) 18
b) 8
c) 0
d) Compiler error
e) None of
above
Output: a)
Explanation:
asm keyword is used to write assembly language program in c. mov
command stores the constants in the register bx, cx etc. add command stores the
content of register and stores in first register i.e. in bx.
Read:
How to write assembly language program by c?
Advance c tutorial.
11. What will be output if
you will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
enum xxx{
a,b,c=32767,d,e
};
printf("%d",b);
return 0;
return 0;
}
a) 0
b) 1
c) 32766
d) Compiler error
e) None of
above
Output: d)
Explanation:
Size of enum constant is size
of sign int. Since value of c=32767. Hence value of d will be 32767+1=32768
which is beyond the range of enum constant.
Read:
Tutorial of data type with
examples.
12. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
signed int a=-1;
unsigned int b=-1;
if(a==b)
printf("%d
%d",a,b);
else
printf("Not
equal");
return 0;
return 0;
}
a) -1 -1
b) -1 32767
c) -1 -32768
d) Not equal
e) Compiler
error
Output: a)
Explanation:
Read:
What is
automatic type conversion?
13. What will be output if
you will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
float f = 5.50f;
float x;
x=f%2;
printf("%f",x);
return 0;
return 0;
}
a) 1.500000
b) 1.000000
c) 5.500000
d) Compiler error
e) None of
above
Output: d)
Explanation:
Read:
Modular division is not
allowed with floating number.
Properties of modular
division.
Operators tutorial with examples.
14. What will be output if
you will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
int a=-20;
int b=-3;
printf("%d",a%b);
return 0;
return 0;
}
a) 2
b) -2
c) 18
d) -18
e) Compiler
error
Output: b)
Explanation:
Sign of resultant of modular
division depends upon only the sign of first operand.
Read:
Properties of modular
division.
Operator’s tutorial with examples.
15. What will be output if
you will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
char c='0';
printf("%d
%d",sizeofc) ,sizeof('0'));
return 0;
return 0;
}
a) 1 1
b) 2 2
c) 1 2
d) 2 1
e) None of
above
Output: c)
Read:
Size of char data type is one
byte while size of character constant is two byte.
Why character constant is of
two byte in c?
16. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
char *url="c:\tc\bin\rw.c";
printf("%s",url);
return 0;
return 0;
}
a) c:\tc\bin\rw.c
b) c:/tc/bin/rw.c
c) c: c inw.c
d) c:cinw.c
e) w.c in
Output: e)
Explanation:
1. \t is tab character which moves the cursor 8 space right.
2. \b is back space character
which moves the cursor one space back.
3. \r is carriage return
character which moves the cursor beginning of the line.
Read:
Complete string tutorial with examples.
Properties of escape characters.
17. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
goto abc;
printf("main");
return 0;
}
void dispaly()
{
abc:
printf("display");
}
a) main
b) display
c) maindisplay
d) displaymain
e) Compiler
error
Output: e)
Explanation:
Label of goto cannot be in
other function because control cannot move from one function to another
function directly otherwise it will show compiler error: unreachable label
Read:
What is goto keyword.
Complete
function tutorial with examples.
18. What will be output if you will compile and execute the following c code?
#include<stdio.h>
18. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
int i=3;
if(3==i)
printf("%d",i<<2<<1);
else
printf("Not equal");
}
a) 1
b) 48
c) 24
d) Not equal
e) Compiler
error
Output: c)
Explanation:
Associative of bitwise left shifting operator is left to right.
In the following expression:
i<<2<<1
There are two bitwise operators. From rule of associative leftmost
operator will execute first.
i <<><<>
After execution of leftmost bitwise left shifting operator:
so i=i*pow(2,2)
=3*
Read:
What is
associative?
What is
precedence?
Tutorial of
bitwise operators.
19. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
int x=2,y=3;
if(x+y<=5)
printf("True");
else
printf("False");
}
a) True
b) False
c) Compiler error: Lvalued required
d) Compiler error: Invalid expression
e) None of
above
Output: a)
Explanation:
Expression x+y<=5
=> 2+3 <=5
=> 5<=5 is true because
5 is either greater than 5 or equal to 5.
Read:
Operator tutorial with examples.
20. What will be output if
you will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
const int i=5;
i++;
printf("%d",i);
return 0;
return 0;
}
a) 5
b) 6
c) 0
d) Compiler error
e) None of
above
Output: d)
Explanation:
We cannot modify the const
variable by using increment operator.
Read:
Properties of
const keyword.
Properties of volatile keyword.
Data type tutorial with examples.
21. What will be output if
you will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
int i=11;
int const * p=&i;
p++;
printf("%d",*p);
return 0;
return 0;
}
a) 11
b) 12
c) Garbage value
d) Compiler error
e) None of
above
Output: c)
Explanation:
In the following line:
int const * p=&i;
*p i.e. content of p is
constant pointer p is not constant pointer. So we can modify the pointer p.
After incrementing the pointer it will point next memory location and its
content will any garbage value.
To make pointer p as constant
pointer write:
int const * const p=&i;
Read:
Properties of const keyword.
Properties
of volatile keyword.
22. What will be output if
you will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
int a=15,b=10,c=5;
if(a>b>c )
printf("Trre");
else
printf("False");
return 0;
return 0;
}
a) True
b) False
c) Run time error
d) Compiler error
e) None of
above
Output: b)
Explanation:
Relation operator in c always
returns 1 when condition is true and 0 when condition is false. So in the
following expression
a > b > c
Associative of relational
operators are left to right order of execution will be following manner:
Since condition a>b is
true so result will be 1. Now expression became:
1 > c
Since this condition is false
so result will be 0. Thus else part will execute.
Read:
What is associative?
What is precedence?
23. What will be output if
you will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
float f;
f=3/2;
printf("%f",f);
return 0;
return 0;
}
a) 1.5
b) 1.500000
c) 1.000000
d) Compiler error
e) None of
above
Output: c)
Explanation:
In the following expression:
f=3/2 both 3 and 2 are
integer constant hence its result will also be an integer constant i.e. 1.
Read:
Properties of floating type numbers.
24. What will be output if
you will compile and execute the following c code?
#include<stdio.h>
#include<stdio.h>
int main(void)
{
int a=sizeofa) ;
a=modifya) ;
printf("%d",a);
return 0;
return 0;
}
int modify(int x)
{
int y=3;
_AX=x+y;
return;
}
a) 2
b) 3
c) 5
d) Garbage value
e) None of above
Output: c)
Explanation:
_AX is register pseudo
variable. It stores return type of function.
Read:
What is register pseudo
variable?
What is global identifier?
25. What will be output if
you will compile and execute the following c code?
#define PRINT printf("c");printf("c++");
int main(void){
float a=5.5;
if(a==5.5)
PRINT
else
printf("Not
equal");
return 0;
return 0;
}
a) c c++
b) Not equal
c) c
c++
d) Compiler error
e) None of
above
Output: d)
Explanation:
First see intermediate file:
try.c 1:
try.c 2: int main(void){
try.c 3: float a=5.5;
try.c 4: if(a==5.5)
try.c 5: printf("c");printf("c++");
try.c 6: else
try.c 7: printf("Not equal");
try.c 8: }
try.c 9: return 0;
try.c 10:
If there are more than one
statement in if block then it is necessary to write inside the { } otherwise it
will show compiler error: misplaced else
Read:
More questions on preprocessors.
Preprocessor tutorial with examples.
26. What will be output if you will compile and execute the following c code?
#include<stdio.h>
26. What will be output if you will compile and execute the following c code?
#include<stdio.h>
int main(void)
{
int array[2][2][3]={0,1,2,3,4,5,6,7,8,9,10,11};
printf("%d",array[1][0][2]);
return 0;
}
a) 4
b) 5
c) 6
d) 7
e) 8
Output: 8
Explanation:
array[1][0][2] means
1*(2*3)+0*(3)+3=9th element of array starting from zero i.e. 8.
Read:
Questions on two dimension
array.
Complete tutorial of array.
