在 Objective-C 中创建字符串

Question

I originally learned Swift. Now, I am trying to learn Objective-C, but I am having some difficulty. They seem a lot more different than I originally thought. Here, I am simply trying to display "Hello World". This is in the .m file.

- (void)viewDidLoad {
[super viewDidLoad];

name = *"World";

NSString word = @"Hello";

self.label.text = [NSString stringWithFormat:@"%@, %@", word, name];


}

In my .h file I have:

@interface ViewController : UIViewController {

NSString *name;

}

Answer 1

In Objective-C variables are declared VariableType variableName = Value; for example

NSInteger number = 10;

If VariableType is an object like NSString you have to add an asterisk and unlike Swift a literal string must start with a leading @ .

NSString *name = @"World";
NSString *word = @"Hello";

self.label.text = [NSString stringWithFormat:@"%@ %@", word, name];

You are encouraged to read Apple's language guide Working with Objective-C

Answer 2

Yeah, Objective-C has some extra symbol stuff going on when compared to Swift. I recommend reading or watching some tutorials on the basics. Also, repetition always helps when learning. The code below should work for you. Be sure to pay attention to the details.

- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

name = @"World";

NSString *word = @"Hello";

self.label.text = [NSString stringWithFormat:@"%@ %@", word, name];

}