why increment Operator Producing such an output

[sonivinay1]

#include<constream.h>
void main()
{
clrscr();
int n=10 ;
int b ;

// 13 13 13
b = ++n + ++n + ++n;
cout<<"\n B = " <<b; //39

n =10;
// 11 12 13
int h = ++n + ++n + ++n;
cout<<"\n H = " <<h; //36

getch();
}

[Repeater]

b = ++n + ++n + ++n;

This does three increments, and three additions. The order in which those happens is undefined.

Could be:

n=n+1;
n=n+1;
n=n+1;
b = n + n + n;

Doesn't have to be. Could be something else. Could be all mixed up. You're doing something that the C++ programming language doesn't specify.


The C++ programming language doesn't say what the "right" order is. There is no "right" order.

Don't do it. Don't do it. Don't do it.