Output of C programs | Set 65 (If-Else)

Prerequisite : Decision making in C
Question 1

C

#include"stdio.h"
#include"stdlib.h"
void reverse(int i)
{
    if (i > 5)
         exit(0);
     printf("%d\n", i);
     return reverse(i++);
}
int main()
{
    reverse(1);
}

OPTIONS: 
a)Segmenation fault 
b)Compilation error 
c)Print 1 Infinite time 
d)Both a & c

OUTPUT:  (d)Both a & c

Explanation: 
We call the main method again and again by 1 because we use post-increment. At certain time stack frame will full means segmentation fault occurs.
Question 2

C

#include"stdio.h"
int main()
{
    if(-1L>1UL)
        printf("paul is crazy");
    else
        printf("mannu is Crazy");
}

OPTIONS: 
a)mannu is Crazy 
b)paul is crazy 

OUTPUT:  (b)paul is crazy 

Explanation: 
Here ,comparison between long int and unsigned long int generally which is not possible. 
Now,long int is promoted to unsigned long int whose value will be 
(2^size_of_unsigned_long_int)-1.
Question 3

C

#include"stdio.h"
int main()
{
    int i;
    if(i=0,2,3)
        printf("Geeksforgeeks ");
    else
        printf("Hello ");
    printf("%d\n",i);
}

OPTIONS: 
a)Hello 3 
b)Hello 0 
c)Geeksforgeeks 0 
d)Geeksforgeeks 3

OUTPUT:  (c) Geeksforgeeks 0

Explanation: At first zero will assign in ‘i’ then comma operator returns the last value which is 3 and condition becomes true.
Question 4

CPP

#include"stdio.h"
int main()
{
    int i;
    if(i=(2,1,0))
        printf("Geeksforgeeks ");
    else
        printf("Hello ");
    printf("%d\n",i);
}

OPTIONS: 
a)Hello 3 
b)Geeksforgeeks 0 
c)Hello 0 
d)Geeksforgeeks 3

OUTPUT:  (c) Hello 0

Explanation: Priority of parenthesis bracket is greater than equal to(=) operator , So atfirst comma operator return the last value which is zero(0) and then equal to(=) operator assign 0 to ‘i’ and condition becomes false.
Question 5

C

#include"stdio.h"
int main()
{
    float a=0.7d;
    if(a<0.7)
         printf("C");
        else
         printf("C++");
    return 0;
}

OPTIONS: 
a)Compilation error 
b)C++ 
c)C

OUTPUT:  (C)C 

Explanation: 
a = 0.7 is rounded to 0.699999988 
and the constant 0.7 is as 0.69999999999 
so a<0.7 is true so it print “c” 
but in case of 0.8 
a = 0.800000011 and 
constant 0.8 is 0.8000000000000000 
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