ios排序知识点函数
排序
Person.h
@interface Person : NSObject
{
int _age;
int _integrity;
NSString * _name;
}
- (id)initWithAge:(int)age andWithIntegrity:(int)i andName:(NSString *)name;
@property (nonatomic) int age;
@property (nonatomic) int integrity;
//左边 大于 右边的准则
- (BOOL)olderThanIntegrity:(Person *)preson;
- (BOOL)youngerThanIntegrity:(Person *)person;
Person.m
#import "Person.h"
@implementation Person
@synthesize age = _age;
@synthesize integrity = _integrity;
- (id)initWithAge:(int)age andWithIntegrity:(int)i andName:(NSString *)name{
if (self = [super init]) {
_age = age;
_integrity = i;
_name = name;
}
return self;
}
//提供一个左边大于右边进行交换的准则 升序;
- (BOOL)olderThanIntegrity:(Person *)person{
// if (self.integrity > person.integrity) {
// return YES;
// }else{
// return NO;
// }
return self.integrity > person.integrity;
}
//降序
- (BOOL)youngerThanIntegrity:(Person *)person{
return self.integrity < person.integrity;
}
- (NSString *)description{
NSString *str = [NSString stringWithFormat:@"name = %@ age = %d 节操 = %d",_name,_age,_integrity];
return str;
}
@end
main
int main (int argc, const char * argv[])
{
@autoreleasepool {
Person *qiange = [[Person alloc]initWithAge:25 andWithIntegrity:0 andName:@"qiange"];
Person *liangge = [[Person alloc]initWithAge:30 andWithIntegrity:-1 andName:@"liangge"];
Person *laoGuo = [[Person alloc]initWithAge:30 andWithIntegrity:80 andName:@"laoguo"];
Person *laoPan = [[Person alloc]initWithAge:30 andWithIntegrity:38 andName:@"laoPan"];
Person *mars = [[Person alloc]initWithAge:35 andWithIntegrity:22 andName:@"mars"];
Person *zhouXiang = [[Person alloc]initWithAge:40 andWithIntegrity:250 andName:@"zhouxiang"];
NSMutableArray *array = [[NSMutableArray alloc]init];
[array addObject:mars];
[array addObject:laoGuo];
[array addObject:qiange];
[array addObject:zhouXiang];
[array addObject:liangge];
[array addObject:laoPan];
//sortUsingSelector:这个是一个排序方法，已经实现了，但是缺少排序准则（升序/降序），（这个准则就是一个函数）
//排序：数组元素应该是相同的对象指针类型
//2.数组元素是哪个类的对象指针，那么我就把这个准则写到这个类中
//3.这个准则就是什么时候交换？？？左边大于右边 交换还是 左边小于右边交换
//升序
[array sortUsingSelector:@selector(olderThanIntegrity:)];//@selector(olderThanIntegrity:)选择器 把函数名转化为选择器
//相当于把olderThanIntegrity:传入sortUsingSelector:中；
[array sortUsingSelector:@selector(youngerThanIntegrity:)];//降序
NSLog(@"array = %@",array);
}
return 0;
}