How can I pass a NSString parameter to a function? - objective-c

Question

I want to initialize an object. The problem is how to pass the NSString correctly.
Object code:
#import "ClaseHoja.h"
#implementation ClaseHoja
#synthesize pares;
#synthesize nombre;
-(id)init
{
self=[super init];
if(self){
}
return self;
}
-(id)initWithValues:(NSString*)nom par:(int)par
{
if([super init]){
pares=par;
nombre=nom;
}
return self;
}
When I call the function I do this:
NSString *nombre="Hello";
int par=20;
ClaseHoja *ch = [ClaseHoja alloc] initWithValues:nombre par:numPares]];

Answer 1

I would suggest:
Add the missing # to #"Hello" and fix the [] in your alloc/init call.
If you're using Xcode, I'd let the compiler synthesize the properties for you. No #synthesize is needed. If you're using a stand-alone LLVM on some other platform, though, you might need it, but by convention, you'd specify an ivar with a preceding _.
I'd define nombre to be copy property and explicitly copy the nombre value passed to your init method. You don't want to risk having a NSMutableString being passed to your method and having it unwittingly mutated without your knowledge.
I'd suggest renaming the initWithValues:par: to be initWithNombre:pares:, to eliminate any doubt about what properties are being updated.
You don't need init without parameters. You can just rely on the one provided by NSObject.
You'd generally use NSInteger rather than int.
In your custom init method, you want to make sure to do if ((self = [super init])) { ... }
Thus:
// ClaseHoja.h
#import Foundation;
#interface ClaseHora: NSObject
#property (nonatomic, copy) NSString *nombre;
#property (nonatomic) NSInteger pares;
- (id)initWithNombre:(NSString*)nombre pares:(NSInteger)pares;
#end
And
// ClaseHoja.m
#import "ClaseHoja.h"
#implementation ClaseHoja
// If you're using modern Objective-C compiler (such as included with Xcode),
// you don't need these lines, but if you're using, for example stand-alone
// LLVM in Windows, you might have to uncomment the following lines:
//
// #synthesize nombre = _nombre;
// #synthesize pares = _pares;
- (id)initWithNombre:(NSString*)nombre pares:(NSInteger)pares {
if ((self = [super init])) {
_pares = pares;
_nombre = [nombre copy];
}
return self;
}
#end
And you'd use it like so:
NSString *nombre = #"Hello";
NSInteger pares = 20;
ClaseHoja *ch = [[ClaseHoja alloc] initWithNombre:nombre pares:pares];

Answer 2

You need to pass like this. Another thing you miss # sign before the string.
NSString *nombre = #"Hello"; int par=20;
ClaseHoja *ch = [[ClaseHoja alloc]initWithValues:nombre par:par];