id question

[OC2000]

Hi,

Why does the underlined code not work?

 Square *mySquare = [[Square alloc]init];
 XYPoint *myPoint = [[XYPoint alloc]init];
   
    id dataValue1; 
    id dataValue2;
   
    dataValue1 = mySquare;
    dataValue2 = myPoint;

    [dataValue1 setSide:5]; // works fine
    [dataValue2 setX:100 andY:200]; // works fine

    dataValue1.origin = dataValue2 // This says that " Member reference type 'struct objc_object *' is a pointer;

    [dataValue1 print];
    [dataValue2 print];

    [mySquare release];
    [myPoint release];

[bpedit]

Try changing the line to
   

Code: (Objective-C)

[dataValue1 setOrigin: dataValue2];

This tested out well for me. I'm not sure why the dot operator does not work in cases like this, it's happened to me before.

[dharr19]

  Square *mySquare = [[Square alloc] init];
    XYPoint *myPoint = [[XYPoint alloc] init];
    
    [myPoint setX:5 andY:10];
    [mySquare setSide:5];
    
    id dataValue1;  
    id dataValue2;
    
    dataValue1 = mySquare;
    dataValue2 = myPoint;
    
    [dataValue1 setSide:5];
    [dataValue2 setX:100 andY:200];
    
    [dataValue1 setOrigin: dataValue2];  
    
    if ( [dataValue1 isMemberOfClass: [Square class]] == YES)
        NSLog(@"mySquare is a member of Square class");
    
    if ( [dataValue2 isMemberOfClass: [XYPoint class]] == YES)
        NSLog(@"mySquare is a member of XYPoint class");

output

2011-08-05 22:28:31.084 GraphicObject[3513:707] dataValue1 is a member of Square class
2011-08-05 22:28:32.159 GraphicObject[3513:707] dataValue2 is a member of XYPoint class