C Programming - C Preprocessor - Discussion

Given answer is wrong the correct answer will be 60, 6.

Because b++ * b++ *b++ will be 3*4*5 which is 60 and b will increase to 6.

I did not understand this output. Can anyone help me?

Yes, 60 6 is right. I agree with it.

Answer Will Be 60,6
How means;

The macro function CUBE(x) (x*x*x) calculates the cubic value of given number(Eg: 103.)

Step 1: int a, b=3; The variable a and b are declared as an integer type and variable b id initialized to 3.

Step 2: a = CUBE(b++); becomes

=> a = b++ * b++ * b++; Here 3++ * 3++ * 3**; Therefore because post increment first time it will be 3 then become 4 then become 5

=> a = 3 * 4 * 5;

=> a = 60; Here, 60 is store in the variable a. By the way, the value of variable b is incremented by 3. (ie: b=6)

Step 3: printf("%d, %d\n", a, b); It prints the value of variable a and b.

Hence the output of the program is 60, 6.

#include<stdio.h>
#define CUBE(x) (x*x*x)
main()
{
int a,b=3;
a=CUBE(++b);
printf("%d, %d\n",a,b);
}

How answer is coming 150, 6?

The answer is 60, 6.

Because (b++*b++*b++),
3*4*5,
60 and b=6;

@Chandu.

At first ++b means b=4,
Then * operator comes,then ++b means b=5,
Then multiplication is done i.e 5*5=25,
Then *, then ++b means b=6,
Then finally 25*6=150, a=150 and b=6.

Value of A and B must be as below:

a= 3*4*5=60;
b=6;

@All.

Different compilers are giving different outputs!

GCC gave 60,6
Turbo C gave 27,6

Which is the correct answer? Please explain it.

In this question, the actual answer is a=60 and b=6.

I compiled and run of this code in Codeblock. Our answer is right theoretically as well as practically but this option is available in this question.

According to C-Language in postfix increment, first we assign the variable's value then we increment it and it is happening in left to right direction.

Soln- a=b++(3)*b++(4)*b++(5)= 3*4*5= 60 and in last we will increase last value of b++(5) with 1 then we found b=6 , so we get final answer is a=60 and b=6 .