//
// Circle.h
// Circle
//
// Created by chicai on 2021/8/18.
//
#import <Foundation/Foundation.h>
NS_ASSUME_NONNULL_BEGIN
@interface Circle : NSObject
{
int rad;
}
-(double)area;//成员方法
-(void)SetRad:(int)_rad;//成员方法
+(id)circle;//静态方法
@end
NS_ASSUME_NONNULL_END
//
// Circle.m
// Circle
//
// Created by chicai on 2021/8/18.
//
#import "Circle.h"
@implementation Circle
-(void)SetRad:(int)_rad
{
self->rad = _rad;
}
-(double)area
{
return 3.14 * rad * rad;
}
+(id)circle
{
return [[self class] new];
}
@end
#import <Foundation/Foundation.h>
#import "Circle.h"
int main(int argc, const char * argv[]) {
@autoreleasepool {
Circle *circle = [Circle circle];
[circle SetRad:20];
NSLog(@"area: %f", [circle area]);
}
return 0;
}