@interface Student :NSObject
@property int age;
-(instancetype)initWithAge;
+(instancetype)studentWithAge;
@end

@implementation Student
-(instancetype)initWithAge{
if(self!=[super init]){

}
}
+(instancetype)studentWithAge;
@end

@interface Student :NSObject
@property int age;
-(instancetype)initWithAge;
+(instancetype)studentWithAge;
@end

@implementation Student
-(instancetype)initWithAge{
if(self!=[super init]){

}
}
+(instancetype)studentWithAge;
@end