Ошибка c2371 переопределение различные базовые типы

I get the error code c2371, for the functions; seperate, longest and shortest. I think its about the input arguments.

error C2371: 'seperate' : redefinition; different basic types
error C2371: 'shortest' : redefinition; different basic types
error C2371: 'longest' : redefinition; different basic types

Code:

#include <stdio.h>

int main(void)
{
  char msg[41];
  int selector = 0;

  printf("Alinur Caglayan - 18050127622 - Lab Work 5 ");
  printf("Please enter a string message with maximum of 40 characters: ");
  gets(msg);

  printf("Please select one of the following functions:\n1) Longest Word Function");
  printf("\n2) Shortest Word Function\n3) Separate Words Function\n4) Exit: ");
  scanf("%d", &selector);

  if(selector == 1)
  {
    longest(msg);
  }
  else if(selector == 2)
  {
    shortest();
  }
  else if(selector == 3)
  {
    seperate();
  }
  else if(selector == 4)
  {
    return 0;
  }
  else
  {
    printf("\nPlease enter a valid integer!\n");
    scanf("%d", selector);
  }
}

char longest(msg)
{
  char *temp = msg, *word = msg, *max = msg;
  int increment = 0, incrementmax = 0;

  do {
    if(!(*temp & ~32)) 
    {
      if(increment > incrementmax) 
      {
        incrementmax = increment;
        max = word;
      }
      increment = 0;
    } 
    else if(!increment++) 
    {
      word = temp;
    }
  } 
  while(*temp++ != 0);

  for(temp = max; (*temp & ~32); ) 
  {
    printf("%c", *temp++);
  }
}

char shortest(msg)
{
  char *temp = msg, *word = msg, *max = msg;
  int increment = 0, incrementmax = 0;

  do {

    if(!(*temp & ~32)) 
    {

      if(increment > incrementmax) 
      {
        incrementmax = increment;
        max = word;
      }
      increment = 0;
    } 
    else if(!increment++)
    {
      word = temp; 
    }
  } 
  while(*temp++ != 0);

  for(temp = max; (*temp & ~32); ) 
  {
    printf("%c", *temp++);
  }
}

char seperate(msg)
{

  char *temp = msg;
  int i;

  printf("Alinur Caglayan - 18050127622 - Lab Work 5 ");
  printf("Please enter a string message with maximum of 40 characters: ");
  gets(msg);

  for(i=0; i < 41; i++)
  {
    if(*temp & ~32)
    {
      printf("\n");
    }
    else
    {
      printf("%c", temp);
    }
    system("pause");
  }
}

There are a lot of errors.

You should declare your functions before main like this:

char shortest(char msg[41]);
char longest(char msg[41]);

or if you don’t want to declare them you could define them before main…

Also you have a:

scanf("%d", selector);

While it should be:

scanf("%d", &selector);

And all your functioncs should return a char too.

Edited: Another thing is that you define your functions like:

char longest(msg) {
    ...
}

But you have to specify the type of the argument, like this.

char longest(char msg[41]) {
    ...
}

answered Nov 30, 2014 at 18:22

You are calling your functions without first declaring their types. This is not allowed in the two latest versions of the C standard, and should result in a diagnostic message.

However, if your compiler complies with an older standard (or none at all), calling an undeclared function will cause the compiler to provide its own declaration with a return type that defaults to int. When you later define the functions to have a different return type, the compiler warns you about the mismatch.

You should always declare your functions (i.e. the return type and the types of its parameters), or in trivial cases, define your functions (i.e. with function body) before you call them.

answered Nov 30, 2014 at 18:11

The following only corrects the basic syntax, without looking into what that sub functions are actually doing:

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

// prototypes
void longest ( char * );
void shortest( char * );
void seperate( char * );

int main(void)
{
    char msg[41];
    int selector = 0;

    printf("Alinur Caglayan - 18050127622 - Lab Work 5 ");
    printf("Please enter a string message with maximum of 40 characters: ");
    if( NULL == fgets(msg, sizeof(msg), stdin) )
    {
        perror( "fgets failed" );
        exit( EXIT_FAILURE );
    }

    int done = 0; // indicate not done

    while(!done)
    { 
        printf("Please select one of the following functions:\n");
        printf( "1) Longest Word Function\n");
        printf( "2) Shortest Word Function\n");
        printf( "3) Separate Words Function\n");
        printf( "4) Exit:\n");

        if( 1 != scanf(" %d", &selector) )
        {
            perror( "scanf failed" );
            exit( EXIT_FAILURE );
        } 

        switch( selector )
        {
            case 1:
                longest(msg);
                break;

            case 2:
                shortest(msg);
                break;

            case 3:
                seperate(msg);
                break;

            case 4:
                done = 1; // cause loop to exit
                break;

            default:
                printf("\nERROR: invalid selection entered\n");
                break;
        } // end switch
    } // end while

    return(0);
} // end funtion: main


void longest( char* msg)
{
    char *temp = msg, *word = msg, *max = msg;
    int increment = 0, incrementmax = 0;

    do {
        if(!(*temp & ~32)) 
        {
            if(increment > incrementmax) 
            {
                incrementmax = increment;
                max = word;
            } // end if

            increment = 0;
        }

        else if(!increment++) 
        {
            word = temp;
        } // end if
    } while(*temp++ != 0);

    for(temp = max; (*temp & ~32); ) 
    {
    printf("%c", *temp++);
    }
} // end function: longest

void shortest(char* msg)
{
    char *temp = msg, *word = msg, *max = msg;
    int increment = 0, incrementmax = 0;

    do {

        if(!(*temp & ~32)) 
        {

            if(increment > incrementmax) 
            {
                incrementmax = increment;
                max = word;
            } // end if
            increment = 0;
        }

        else if(!increment++)
        {
            word = temp; 
        }
    } while(*temp++ != 0);

    for(temp = max; (*temp & ~32); temp++) 
    {
        printf("%c", *temp);
    }
} // end function: shortest

void seperate(char* msg)
{

    char *temp = msg;
    int i;

    printf("Alinur Caglayan - 18050127622 - Lab Work 5 ");
    printf("Please enter a string message with maximum of 40 characters: ");
    if( NULL == fgets(msg, sizeof(msg), stdin) )
    {
        perror( "fgets failed" );
        exit( EXIT_FAILURE );
    }

    for(i=0; i < 41; i++)
    {
        if(*temp & ~32)
        {
            printf("\n");
        }
        else
        {
            printf("%c", temp);
        }  // end if

        system("pause");
    } // end for
} // end function: seperate