OC基础之选择器的使用
FJAnimal.h
#import <Foundation/Foundation.h>
@interface FJAnimal : NSObject
@property(nonatomic,copy) NSString *name;
/**定义一个动物的父类，属性名字*/
+ (instancetype) animalWithName:(NSString *)name;
/**玩耍*/
- (void) play;
/**吃东西*/
- (void) eat;
@end
FJAnimal.m
@implementation FJAnimal
+ (instancetype)animalWithName:(NSString *)name{
return [[self alloc]initWithName:name];
}
- (instancetype)initWithName:(NSString *)name{
if (self = [super init]) {
_name = name;
}
return self;
}
- (void)play{
NSLog(@"%@正在玩耍!",_name);
}
- (void) eat{
NSLog(@"%@正在吃东西!",_name);
}
@end
FJCat.h
#import "FJAnimal.h"
@interface FJCat : FJAnimal
/**猫特有的动作：爬树*/
- (void) climbTheTree;
@end
FJCat.m
#import "FJCat.h"
@implementation FJCat
- (void)climbTheTree{
NSLog(@"%@正在爬树！",self.name);
}
FJDog.h
#import "FJAnimal.h"
@interface FJDog : FJAnimal
/**猫特有的动作看门*/
- (void) keepTheDoor;
@end
FJDog.m
#import "FJDog.h"
@implementation FJDog
- (void)keepTheDoor{
NSLog(@"%@可以看门",self.name);
}
@end
main.m
#import <Foundation/Foundation.h>
#import "FJCat.h"
#import "FJDog.h"
//通过传入第三个参数，传入一个指向函数的指针让函数中要做的运算不再是程序中的硬代码
// 指向函数的指针实现了代码的解耦合，让函数更加通用
int foo(int *arr,int n,int (*p)(int ,int )){
int sum = arr[0];
for(int i=0;i<n;i++){
sum= p(sum,arr[i]);
}
return sum;
}
int add(int a,int b){
return a+b;
}
int sub(int a,int b){
return a-b;
}
int mul(int a,int b){
return a*b;
}
void bar(id obj,SEL sel,id param){
if ([obj respondsToSelector:sel]) {
[obj performSelector:sel withObject:param];
}
}
int main(int argc, const char * argv[]) {
@autoreleasepool {
int x[] = {1,2,3,4,5};
printf("%d\n",foo(x, sizeof x/sizeof x[0], add));
printf("%d\n",foo(x, sizeof x/sizeof x[0], sub));
printf("%d\n",foo(x, sizeof x/sizeof x[0], mul));
FJCat *cat = [FJCat animalWithName:@"cat"];
FJDog *dog = [FJDog animalWithName:@"dog"];
bar(cat, @selector(climbTheTree), nil);
bar(dog, @selector(keepTheDoor), nil);
}
return 0;
}