Question

I want to create an object called Note . Then I want to assign some values to it’s fields and display them in the console to verify that all of this works properly.

       Note.h
#import <Foundation/Foundation.h>

@interface Note : NSObject
{
    NSNumber *position;
    NSString *syllable;
}
@property(nonatomic, retain)NSNumber *position;
@property(nonatomic, retain)NSString *syllable;
@end

    Note.m

#import "Note.h"

@implementation Note
@dynamic position;
@dynamic syllable;
@end

After this , in another class I want to assign some values to the fields .

-(void) configNote:(Note*)not
{
    not = [Note alloc];
    [not setPosition:[NSNumber numberWithInt:2]];
    [not setSyllable:@"Twin-"];
}


.....
 Note *note;

 [self configNote:note];

 NSLog(@" pos : %d syl : %@ ",[[note position] integerValue],[note syllable]); 

I tried to use @synthesize instead of @dynamic but still nothing changes . The reason of the error is : -[Note setPosition:]: unrecognized selector sent to instance 0x733d060

Answer 1

init your note and use custom init method to initialize ivars and change dynamic to synthesize
and for better use this init to initialize your varibales

- (id)initWithPosition:(NSNumber*)pos andSyllable:(NSString*)syl {
    self = [super init];
    if (self) {
        self.position = pos;
        self.syllable= syl;
    }
    return self;
}