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Point et ColorPoint in Objective-C 

#import <appkit/appkit.h>



@interface Point : Object
{// instance variables
 int x;
}
- (int) getx; 

- setx:(int) y;
@end



@implementation Point
- (int) getx
        { return x;}
- setx:(int) y
        { x=y; return self;}  

@end



@interface ColorPoint : Point
{// instance variables
char * col;
}
- (char ) getcol;

- setcol:(char ) c;  

@end



@implementation ColorPoint : Point
- (char ) getcol
        { return col;}
- setcol:(char ) c
        { free(col);
          col=(char *)malloc(strlen(c));strcpy(col,c);
          return self;}
@end



main() {
id p, cp;



p=[[Point new] setx: 3];
cp=[[[ColorPoint new] setx: 4] setcol: "blue"];



printf("Point at %d, %s ColorPoint at %d\n",
       [p getx], [cp getcol], [cp getx]);
exit(0);
}


Roberto DiCosmo
Mon Jun 3 18:29:31 MET DST 1996