成员变量

Student.h:

#import <Foundation/Foundation.h>

@interface Student : NSObject{
    //    @public
    //    @private
    //    @protected
    //y一般默认的情况是@protected
    int age;
    @private
    int no;
    @public
    float height;
}
//-(void) age;
@property(nonatomic,assign) int age;
@end

Student.m:

#import "Student.h"

@implementation Student

@end

GoodStudent.h:

#import "Student.h"

@interface GoodStudent : Student

@end

GoodStudent.m:

#import "GoodStudent.h"

@implementation GoodStudent
-(void) test{
    age=10;
    //no=9;
    height=0.1f;
}
@end

main:

#import <Foundation/Foundation.h>
#import "Student.h"
int main(int argc, const char * argv[])
{

    @autoreleasepool {
        
        Student *stu=[[[Student alloc] init] autorelease];
        //点语法不是访问成员变量，是访问get和set方法
        stu.age=10;
        //通过get方法调用成员变量
        NSLog(@"age is %i",stu.age);
        //这样才是访问@public成员变量
        stu->height=10.9f;
        NSLog(@"height is %.1f",stu->height);
        
    }
    return 0;
}

结果：

2013-08-02 15:12:25.051 成员变量[988:303] age is 10

2013-08-02 15:12:25.072 成员变量[988:303] height is 10.9