Understanding increment operator with pointers in C

[WhiteDeviL]

Hello Cprogramming Community, I need some clarification about this particular code below:

#include <stdio.h> 
#include <stdlib.h> 
#include <string.h> 


int main(void)
{
    char phrase[80],*p;
    int i,s=0;
    gets(phrase);
    p=phrase;

    while (*p!='\0')
        if (*(p++)==' ') s++;
    printf("Phrase has %d spaces.\n",s);
    
    return 0;
}

My question is, why p++ will get incremented after the if statement?
Shouldn't it be the opposite?
I really would like some explanation on that behavior here!

Thanks in advance for your time!

[laserlight]

You might want to revise your learning material on pre-increment versus post-increment; you may have mixed them up hence the confusion.

[rstanley]

Please take a look at the following to see the difference between pre and post increment operators:

#include <stdio.h>

int main(void)
{
   int x = 10;
   int y = 0;

   // Pre-increment
   printf("%s\n", "Increment x before assigning the value to y");
   printf("Original x == %d\n", x);
   y = ++x;
   printf("x == %d\n", x);
   printf("y == %d\n\n", y);

   x = 10;
   // Post-increment
   printf("%s\n", "Increment x after assigning the original value to y");
   printf("Original x == %d\n", x);
   y = x++;
   printf("x == %d\n", x);
   printf("y == %d\n", y);

   return 0;
}

And the result:

$./foo
Increment x before assigning the value to y
Original x == 10
x == 11
y == 11

Increment x after assigning the original value to y
Original x == 10
x == 11
y == 10

Also, NEVER use gets()! gets() has been depreciated in C99 and removed completely from the C11 C Standard. Please use fgets() instead!

[WhiteDeviL]

Thanks for the answer, I was confused a bit with unary operators when I posted this and the only reason I used gets() was because the book I was reading had this as a solution to an exercise.