Let's talk about datatypes

[Faskist]

So, this morning, I wrote a simple program to sate my curiosity (Such is all hacking) about something I'd never bothered to find out -- just how big is the memory allocated to the datatypes we use everyday?

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

int main()
{
  int i;

  i = sizeof(char);
  
  printf( "A char is this big: |" );
  while( i > 0)
    {
      printf( "-" );
      --i;
    }
  printf( "|\n" );
  
  i = sizeof(int);
  
  printf( "An int is this big: |" );
  while( i > 0)
    {
      printf( "-" );
      --i;
    }
  printf( "|\n" );
  
  i = sizeof(short);
  
  printf( "A short is this big: |" );
  while( i > 0)
    {
      printf( "-" );
      --i;
    }
  printf( "|\n" );
  
  i = sizeof(long);
  
  printf( "A long is this big: |" );
  while( i > 0)
    {
      printf( "-" );
      --i;
    }
  printf( "|\n" );
  
  return 0;
}

I know the code seriously needs refactoring, and it could be cleaned up so much, but I just wanted a quick solution.

The answer you'll get depends on platform, but in mine... int is as big as long!! The horror! The bloat!

 

[Nullware]

That's because with your compiler (and mine) integers and longs are able to take on the same values (-2147483648 to 2147483647). The more common integer we're used to (-32768 to 32767) is changed to be called short int.

 

[Faskist]

That's so redundant, lol. How does I changed long to 8 bytes?

 

[Govind]

__int64?

 

[Cruel__Machine]

Yup, int = long.

I at least prefer this to VB making Integer = Short. So I always accidentally use Integer instead of Long. Or I used to at least, I don't use VB much these days.

I know how to do 64bit math with 32bit registers. At least I used to... it's all kind of blurry... I haven't used asm in like a year. :'(

 

Of course an int is the same size as a long. Both are 32 bit full words on x86.

Incidentally, that code is incredibly roundabout. All you needed was one printf:

C:\DOCUME~1\RICHAR~1>type tmp.c
#include <stdio.h>

int main() {

printf("char %d, int %d, long %d, double %d", sizeof(char), sizeof(int), sizeof(long), sizeof(double));

}

C:\DOCUME~1\RICHAR~1>gcc tmp.c

C:\DOCUME~1\RICHAR~1>a
char 1, int 4, long 4, double 8

 

[Faskist]

Of course an int is the same size as a long. Both are 32 bit full words on x86.

Incidentally, that code is incredibly roundabout. All you needed was one printf:

I actually wrote some code very similar to that when discussing it on a textboard, but my code produces a nice pretty (almost) graphical representation of it (And could still be improved and refactored).