Java class to objective-C class

Question

i need to know what is the equivalent code for the code below in Objective-C

public MyClass(int x, int y) {
        xCoOrdinate = x;
        yCoOrdinate = y;
    }

    public int getXCoOrdinate() {
        return xCoOrdinate;
    }

    public int getYCoOrdinate() {
        return yCoOrdinate;
    }
    public MyClass func() {
        return new MyClass(xCoOrdinate - 1, yCoOrdinate);
    }

this is what i tried :

    -(id)initWithX:(int )X andY:(int)Y
{
    if(self = [super init])
    {
        self.xCoOrdinate = X;
        self.yCoOrdinate = Y;

    }
    return self;
}
-(MyClass *)func
{

    return [self initWithX:(self.xCoOrdinate -1)  andY:self.yCoOrdinate];
}

is this a right way ?

Are you compiling with or without ARC, and is this code targeting iOS or OS X? — jlehr, Apr 06 '12 at 12:53

Richard J. Ross III · Answer 1 · 2012-04-07T14:19:41.697

4

No. You need to return a new instance of the class:

-(MyClass *)func
{
    return [[[[self class] alloc] initWithX:(self.xCoOrdinate - 1)  andY:self.yCoOrdinate] autorelease];
}

Notice we use [[self class alloc] to create a new instance of the current class, MyClass.

edited Apr 07 '12 at 14:19

answered Apr 06 '12 at 12:39

Richard J. Ross III

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The new instance should be autoreleased because, according to Cocoa's memory management conventions, a method named "func" would not return an owned object. – Ken Thomases Apr 07 '12 at 06:46

Dr.Kameleon · Answer 2 · 2012-04-06T12:59:31.050

1

A few corrections :

public int getXCoOrdinate() {
    return xCoOrdinate;
}

would become :

- (int)getXCoOrdinate
{
    return [self xCoOrdinate];
}

and

public MyClass func() {
    return new MyClass(xCoOrdinate - 1, yCoOrdinate);
}

would become :

+ (MyClass*)func
{
     MyClass* newFunc = [[MyClass alloc] initWithX:0 Y:0];

     if (newFunc)
     {
     }
     return newFunc;
}

edited Apr 06 '12 at 12:59

answered Apr 06 '12 at 12:40

Dr.Kameleon

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The getter is unnecessary, he creates the variables as properties, as shown by his syntax. – Richard J. Ross III Apr 06 '12 at 13:09
@RichardJ.RossIII I just tried to explain HOW it should be done in a general fashion. Of course, if he uses `@property` no getters/setters may be needed... – Dr.Kameleon Apr 06 '12 at 13:16
The convention in Objective-C is not to prefix getters with "get". You should just call it `xCoordinate` – JeremyP Apr 06 '12 at 13:50
@JeremyP Good point. I know, of course. Though I tried NOT to confuse the OP (I just decided to stick to his way of naming the functions). – Dr.Kameleon Apr 06 '12 at 14:04

Java class to objective-C class

2 Answers2