Question

I am learning Objective C

I have the following trouble.

If I use the libretto NSObject my program work fine,
but if I change to use the library Object.h,
the program doesn’t work.

The code is:

//-------------------------------------------------------------
/* Saludar.h */
//-------------------------------------------------------------
#import <objc/Object.h>

@interface  Saludar : Object
{
    char* strSaludo;
}
- (id)init;
- (void)setSaludo:(char*)sSaludo;
- (void)setSaludo:(char*)sSaludo y:(char*)sMensaje;
- (void)subSaludar;
@end

// ---------------------------------------------------------------
// Saludar.m
// ---------------------------------------------------------------
#import "Saludar.h"
#import <stdio.h>
#import <stdlib.h>
#import <string.h>

@implementation Saludar

- (id)init
{
    if (self = [super init])
    {
        strSaludo = "Programando en Objective-C";
    }
    return self;
}

- (void)setSaludo:(char*)sSaludo
{
    strSaludo = sSaludo;
}

- (void)setSaludo:(char*)sSaludo y:(char*)sMensaje
{
    // Reserva memoria para el Mensaje
    strSaludo = malloc(strlen(sSaludo)+strlen(sMensaje)+1);

    // Copia el Saludo y el Mensaje
    strcpy(strSaludo,sSaludo);
    strcat(strSaludo,sMensaje);

}

- (void)subSaludar
{
    // Desplliega el Saludo
    printf("%s\n",strSaludo);
}
@end


//--------------------------------------------------------
// Clase01.m
//--------------------------------------------------------
#import "Saludar.m"

int main()
{

    //printf("Entra al Programa\n");
    Saludar* s = [[Saludar alloc] init];


    //printf("Va a Saludar\n");
    [s subSaludar];
    [s setSaludo:"Hola Jaor"];
    [s subSaludar];
    [s setSaludo:"Hola Jaor " y:"Long Live to Programming"];
    [s subSaludar];

    [s free];
    return EXIT_SUCCESS;
}

It’s like it doesn’t recognize the super class ‘super’ or doesn’t recognize
the message ‘init’.

The messages ‘alloc’ and ‘free’ aren’t recognized.

This is all message

n Framework GNU\Saludar.m||In function ‘-[Saludar init]’:| n Framework
GNU\Saludar.m|11|warning: ‘Object’ may not respond to ‘-init’ [enabled
by default]| n Framework GNU\Saludar.m|11|warning: (Messages without a
matching method signature [enabled by default]| n Framework
GNU\Saludar.m|11|warning: will be assumed to return ‘id’ and accept
[enabled by default]| n Framework GNU\Saludar.m|11|warning: ‘…’ as
arguments.) [enabled by default]| n Framework GNU\Clase02a.m||In
function ‘main’:| n Framework GNU\Clase02a.m|8|warning: ‘Saludar’ may
not respond to ‘+alloc’ [enabled by default]| n Framework
GNU\Clase02a.m|18|warning: ‘Saludar’ may not respond to ‘-free’
[enabled by default]| ||=== Build finished: 0 errors, 6 warnings ===|

The program runs, but doesn’t display messages, doesn’t work.

Answer 1

You should subclass NSObject, not Object. Object is part of the Apple/GNUStep runtimes as a legacy class, but is not used for new development.