How To Pass a Dictionary To a Function - iphone

Question

Alright, so I think I'm doing this the right way. I'm new to objective-C, so I'm not sure about the syntax... I have a set of code that I need to call multiple times, from different files. So I made a new class that has a method in it that I'll call and pass it the values that it needs.
Because I am passing different values I've put them in a dictionary and decided to just pass the dictionary. Here is that code:
NSNumber *testNum = [NSNumber numberWithInt:varMoney];
NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
[dictionary setObject:#"OMG, Object 1!!!!" forKey:#"1"];
[dictionary setObject:#"Number two!" forKey:#"2"];
[dictionary setObject:testNum forKey:#"3"];
This code creates a test variable, and then puts it into the dictionary "dictionary." That all works, I have my nice little dictionary. However, now I need to create the class and it's method that will recieve the dictionary, and do something with it.
This is my class header file:
#import <UIKit/UIKit.h>
#interface EndOfTurnObjC : UIView {
}
#end
And this is the implementation file:
#import "EndOfTurnObjC.h"
#implementation EndOfTurnObjC
- (id)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
// Initialization code
}
return self;
}
- (void)dealloc {
[super dealloc];
}
#end
I haven't created any of the real code, because I'm not sure how to do the passing. I need to create a function (Method?) in the class that will take a Dictionary has a parameter, and then return the dictionary.
I also have no idea how to call such a function because it's in the class. So, the questions are:
1: How do I define the method in the class to accept the dictionary as a parameter (and then perhaps some example code to pull out one of the objects in a dictionary, so I can be sure it works)
2: How do I return the dictionary at the end of the method?
3: How do I call this method, in the class, from another class? (I know it involves making an object of thing class and calling the method of the object... I think, but I'm not sure about the syntax.)
Please include relavent code for the 3 files (header, implementation, and the other class that I call from). Thank you so much, I've been working on this particular problem for a while now.

Answer 1

Apple's The Objective-C Programming Language is a good and pretty concise reference for Objective-C syntax. What you want is just a normal method that takes an NSDictionary as a parameter. So as given in that document:
A message with a single argument affixes a colon (:) to the selector name and puts the argument right after the colon. This construct is called a keyword; a keyword ends with a colon, and an argument follows the colon, as shown in this example:
[myRectangle setWidth:20.0];
So a method call to pass dictionary would look like:
[someObject setAttributes:dictionary];

Answer 2

In the header:
-(NSMutableDictionary *) doSomethingWithDictionary:(NSMutableDictionary *) aDict;
in the implementation:
-(NSMutableDictionary *) doSomethingWithDictionary:(NSMutableDictionary *) aDict{
//do something with the dictionary
return aDict;
}
To call the method:
NSMutableDictionary *returnDict=[EndOfTurnObjC doSomethingWithDictionary:dictionary];
Note that as a matter of good design you wouldn't want to pass a mutable dictionary around like a token. That is asking for trouble. Instead pass static dictionaries and get another dictionary back.
You also shouldn't be passing data to a UIView. Instead, your UIViewController should process the data and then populate the view's UI elements as needed.

Answer 3

if you just want to do stuff to your dictionary u just
-(void) changeMyDictionary:(NSMutableDictionary * ) dictionary_
{
[dictionary_ doStuff];
....
...
}
no need to return the dictionary.