Do ivars have to be enclosed in curly braces?

Question

Is it mandatory to enclose instance variables in braces? Or is it just convention?

For example:

#import <Foundation/Foundation.h>    

@interface Person : NSObject
{
    NSString *name;
    int age;
}

I don't understand what you've written here. The examples I'm finding on the Internet for the `#import` directive look like this: `#import "Point.h"` `#import ` — Robert Harvey, Apr 26 '14 at 22:23
possible duplicate of [Where to put iVars in "modern" Objective-C?](http://stackoverflow.com/questions/13566862/where-to-put-ivars-in-modern-objective-c) — Black Frog, Apr 26 '14 at 22:40

score 5 · Accepted Answer · answered Apr 26 '14 at 22:27

5

Yes, the curly braces are required to declare instance variables. Curly braces right after an @interface or @implementation line mark instance variable declarations. If you omitted the braces, you would simply be declaring global variables.

answered Apr 26 '14 at 22:27

Chuck

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tompave · Answer 2 · 2014-04-26T22:30:24.937

the curly braces and the enclosed block are used to declare the instance variables of an Objective-C class, and follow a @interface or @implementation declaration.

You can declare variables outside these blocks, but they will use raw C semantics.
For example, Objective-C has instance and class methods, but it doesn't have a clear concept of class variable.
You can still use class variables, with C semantics.

static NSMutableArray *myClassList;

@implementation Person
{
    // this block is actually optional
}

// instance methods
// ...

@end

Do ivars have to be enclosed in curly braces?

2 Answers2