Question

I’m setting a string in a view controller called ViewController and trying to access it somewhere else. This is the code:

ViewController.h

NSString *string;

...

@property (retain) NSString *string;

ViewController.m

@synthesize string;

...

-(void)viewDidLoad {

...

string = @"Test";

}

OtherViewController.m

#import "ViewController.h"

...

-(void)viewDidLoad {

    ViewController *vc;
    vc = [[ViewController alloc] init];

    NSLog(@"String: %@", vc.string);

}

However, the log is showing: String: (null). What am I doing incorrectly? Thanks.

Answer 1

edit : it doesn’t necessarily need to be an NSObject class, if you want to, you could also do this on your viewController class, just be sure to also include

-(id)init

on your header

—- end of edit

if you’re trying to make a class that’s accessible to another view controller, why not try NSObject instead of view controller (considering you only need to take that string value)

for instance, lets call that viewController class “global” class

so at global.h, you put up

#import <Foundation/Foundation.h>

@interface GlobalVar : NSObject

@property (nonatomic, strong) NSString *myString;


-(id)init;

@end

and then, at global.m you put up

#import "GlobalVar.h"

@implementation GlobalVar

@synthesize myString;

-(id)init
{
    self = [super init];
    if(self)
    {
        myString = [[NSString alloc]initWithFormat:@"the String"];
    }

    return self;
}



@end

after this, everytime you need to access the “myString” object that contained in global class, you could put up

at header :

#import "GlobalVar.h"
...
...
@property (nonatomic, strong) GlobalVar *globalVar;

at implementation file :

@synthesize globalVar;

...
...

self.globalVar = [[GlobalVar alloc]init];
NSString *theString = globalVar.myString;
NSLog(@"content of my string is : %@",theString);

there you go 😉