1、Person.h
#import <Foundation/Foundation.h> @interface Person : NSObject { NSString *_name; int _age; } -(void)setName:(NSString *) name andAge:(int) age; -(void)say:(NSString *)content; -(NSString *)info; +(void)foo; @end
Person.m
#import "Person.h" @implementation Persion { int test; } -(void)say:(NSString *)content { NSLog(@"%@", content); } -(NSString *)info { [self test]; return [NSString stringWithFormat:@"名字:%d, 年龄%d,", _name, _age]; } +(void)foo { NSLog(@"通过类名调用"); } -(void)test { NSLog(@"this is a test method"); } @end -(void)setName:(NSString *) _name andAge:(int) _age { //记得这里是self->_name不是self._name,一定要注意。 self->_name = _name; self->_age = _age; } Person *person = [[Person alloc] init]; [person say:@"hello"]; [person setName:@"chenyu" andAge:26]; NSString *info = [person info]; NSLog(@"info is %@", info); [Persion foo];
2、id类型可以代表所有对象的类型，可以任何类的对象赋值给id类型变量
id p = [[Person alloc] init];
[p say:@"hello"];
3、oc没有类变量，但是可以通过内部全局变量来模拟类变量
oc也提供了static关键字，但是static不能用于修饰成员变量，只能修饰局部变量，全局变量和函数，static修饰局部变量表示将该局部变量存储在静态存储区，static修饰全局变量用于限制全局变量只能在当前源文件中访问，static修饰函数用于限制函数只能在当前文件中调用
模拟类变量
User.h文件如下
#import <Foundation/Foundation.h> @interface User : NSObject +(NSString *)nation; +(void)setNation:(NSString *)newNation; @end
User.m文件如下
#import "User.h" @implement User static NSString *nation = nil; +(NSString *)nation { return nation; } +(void)setNation:(NSString *)newNation { nation = newNation; } @end int main(int argc, char* argc[]) { @autoreleasepool { [User setNation:@"chenyu"]; NSLog(@"nation is %@", [User nation]); } }
4、单例模式
Singleton.h文件如下
#import <Foundation/Foundation.h> @interface Singleton : NSObject +(id)instance; @end
Singleton.m文件如下
@implemnet Singleton static id instance = nil; +(id)instance { if (instance) { instance = [[super malloc] init]; } return instance; } @end int main(int argc, char* argc[]) { @autoreleasepool { NSLog(@"%d", [Singleton instance] == [Singleton instance]); } }
