对象方法利用"self->成员变量名"访问当前对象内部的成员变量
#import <Foundation/Foundation.h>

@interface Person : NSObject
{
    int _age;
}
- (void)test1;
- (void)test2;
@end

@implementation Person
- (void)test1
{
    _age = 20;
    [self test2];
}
- (void)test2
{
   
    int _age = 10;
    NSLog(@"调用了-test2方法-%d", self->_age);
}
@end

int main()
{
    Person *p = [Person new];
    [p test1];
    return 0;
}

//输出：调用了-test2方法-20

对象方法利用"self->成员变量名"访问当前对象内部的成员变量
#import <Foundation/Foundation.h>

@interface Person : NSObject
{
    int _age;
}
- (void)test1;
- (void)test2;
@end

@implementation Person
- (void)test1
{
    _age = 20;
    [self test2];
}
- (void)test2
{
   
    int _age = 10;
    NSLog(@"调用了-test2方法-%d", self->_age);
}
@end

int main()
{
    Person *p = [Person new];
    [p test1];
    return 0;
}

//输出：调用了-test2方法-20