Question

Explainthe order in which the operators and

Side effects take place. Justify the explanation based on the output of program.

program:

#include <stdio.h>

int f(int *a)
{
   *a *= 2;
   printf("(%d)", *a);
   return *a + 1;
}

int main()
{
   int x = 2, z = 0;
   printf("lab8c: ");
   z = !f(&x)?--z:f(&z);
   printf("   x %d, z %d\n", x, z);
}

output:

lab8c: (4)(0)   x 4, z 1

Answer 1

The answer to this question is as follows:

The explanation is as follows:

The major operations are used are conditional operation and then 0 means true and 1 means false

i,e if the integer value other than 0 is false and then we are using the not operator and then passing the address of the value to the pointer variable

and we are using the pre-decrement operator also it decrements the value before assigning to any variable;

The statement  z = !f(&x)?--z:f(&z);

Here the execution starts before the left-hand side of the question mark i.e !f(&x)

step1:

The value that is passing to the function is x=2

then *a=a*2 then a=2 then we the value of a=2*2=4

first, it will print the value lab8c:

then print the (4) then returning the value 5

then we are checking !f(5) i.e !5 will give the value i,e !true results the value false

if it is false then the statement f(&z) the initial value of z=0

Step 2:

Then executing the function again we are passing value the value 0 then printing the value

(0)

and returning the value 1 and it is assigned to z

z=1

then print the value of the x and z

it prints the x 4 , z 1