struct

[goran00]

I have the following program. Everything seems ok, the only problem is that the wight always prints 0.
How can i fix that

#include <time.h>
#include <stdio.h>
#include <stdlib.h> 
#define TRUE 1
#define FALSE 0  

void printCat(CAT);

//void compare (CAT, cat27, max);

typedef struct {	
	double weight;	
	char name[50];	
	int neutered;
}CAT;  
	int main(){	
		int size=0; 
		int index=0;
		int i;
		CAT* heardOfCats;
		char*name[6]={"Fluffy", "Tigger", "Max", "Betty", "Cat27","Jake"};	
		CAT max;
		srand(time(NULL));
		
		
		
		printf("Please enter the number of cats: ");	
		scanf("%i", &size);
		
		
		 	
		heardOfCats=calloc(size, sizeof(CAT));
		
			
		strcpy(max.name,"Max");	
		max.weight=12;	
		max.neutered=TRUE; 	
	
		printCat(max);	
		
		

		for(i=0; i<size; i++){
		index = rand() % 6;
		strcpy(heardOfCats[i].name, name[index]);
		heardOfCats[i].neutered=rand()%2;
		printf("%s    ",heardOfCats[i].name);
		printf(" %i   ", heardOfCats[i].weight);
		printf("%i     ",heardOfCats[i].neutered);
		printf("\n");
		}
		
		system("Pause");}   

	void printCat(CAT max){	
		printf("%s\n", max.name);	
		printf("%.1lf\n", max.weight);	
		printf("%i\n", max.neutered);}

[master5001]

Certainly the fact main() isn't actually returning anything doesn't exactly qualify as ok, but I am not here to pick on your code.

Its good practice to pass structs by reference rather than by value.

Example

void printCat(const CAT *max)
{
  const char *boolStr[2] = {"false", "true",};  /* Corrected */
  printf("%s\n%.1lf\n%s\n", max->name, max->weight, boolStr[max->neutered]);
}

Secondly, I don't see anywhere that you are actually setting anything other than name of the cats.

[JFonseka]

Firstly when compiling ALWAYS USE -Wall

Your string library is missing. Your main function should be returning something, 0.

printf(" %f   ", heardOfCats[i].weight);

And your formatting needs to be improved

[Elysia]

Its good practice to pass structs by reference rather than by value.

By pointer, please. By pointer. By reference is misleading.

Firstly when compiling ALWAYS USE -Wall

Who says goran00 is using GCC? It's bad to assume.

Also, as someone mentions, you need to work on your indenting,
http://cpwiki.sourceforge.net/Indentation
http://cpwiki.sourceforge.net/User:Elysia/Indentation

I spot two other subtle errors in your program too.

char*name[6]={"Fluffy", "Tigger", "Max", "Betty", "Cat27","Jake"};

Firstly, this should be const char, not char. A string literal is const. Also note how you have 6 names.

index = rand() % 6;
strcpy(heardOfCats[i].name, name[index]);

Note that this could possibly result in 6 which is beyond the end of your name array.

[matsp]

index = rand() % 6;

will NEVER be 6 - it will be a number in the range 0..5, so it's correct in relation to the array posted.

Compare:

  const char *boolStr[2] = {"true", "false"};

with:

#define TRUE 1
#define FALSE 0

If TRUE is 1, then I suggest that boolStr[] should have "true" on index 1, not index 0.

And finally:

printf("%.1lf\n", max.weight);

in C99 will print a "long double" number - if you are NOT using a C99 compatible(-ish) compiler, it may do "anything". Note that this printf and scanf are different in the treatment of the "%lf" format specifier.


--
Mats

[master5001]

The boolStr[] was my bad. It was late...

It would never hurt your code to actually do some error checking too. I suppose it depends on what the program is for, but scanf() has some perils to be aware of that can easily be avoided if one just makes sure scanf() read what it was supposed to read.

Though I am sure while debugging your code you are not entering "a" or something when it prompts for the size, if someone else is using it, that could be a reasonable issue.