Thread: Problem with function identifiers-

Hi all. I'm a mechanical engineer and new to this forum. I'm doing some refresher courses on C and am trying to figure out why my program is erroring out on me. I'd appreciate any help. The program is a basic bubble sort, but when I try to compile I get

error C3861: 'bubblesort': identifier not found

Thanks a bunch. I'm working in Visual Studio C++ Express

Code:

// mod9_7.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <stdio.h>
#include <iostream>
#define SIZE 10
using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
	int i, arraybub[SIZE];

	printf("Enter 10 integers to sort: \n");

	for(i = 0; i < SIZE; i++)
	{
		printf("Integer %d: \n", i+1);
		scanf("%d", &arraybub[i]);
	}

	printf("\nArray before sort: \n");
	
	for(i = 0; i < SIZE; i++)
		printf("%d, ", arraybub[i]);

	bubblesort(arraybub, SIZE);

	printf("\nArray after sort: \n");
	
	for(i = 0; i < SIZE; i++)
		printf("%d, ", arraybub[i]);

	return 0;
}


void bubblesort(int array[], int nitems)
{
  int i, j, temp;

  for (i = 0; i < nitems - 1; i++)
    for (j = i + 1; j < nitems; j++)
      if (array[i] > array[j]) {
        temp = array[i];
        array[i] = array[j];
        array[j] = temp;
      }
}

C and C++ read files from the top down. Before you can use a function the compiler must know about it. Therefore you must prototype the bubblesort function by adding the function signature to the file before it's used. The function signature is:

Code:

void bubblesort(int array[], int nitems);

Originally Posted by rags_to_riches

C and C++ read files from the top down. Before you can use a function the compiler must know about it. Therefore you must prototype the bubblesort function by adding the function signature to the file before it's used. The function signature is:

Code:

void bubblesort(int array[], int nitems);

Holy crap, how did I miss that. That's what you get when you program while trying to comfort a sick 1 year-old in the middle of the night. Thanks Rags.

Just offering an alternative solution. You can avoid the forward declaration if you move the implementation of bubblesort before main. Not always desirable, but I thought I'd point out all the ways to deal with the problem.