OC中数组排序总结

>过完节回来，感觉很多东西都生疏了。总结一下数组的排序。应该不会太完美，后续添加补充。 ##OC中的数组排序方法其实不太多，要根据不同的使用场景来使用不同的方法。Foundation框架中一般用到一下几个方法。 ###1.sortedArrayUsingSelector 此方法一般用于且NSNumber、NSString的基础数据数组排序，默认升序。 举个???? ``` NSArray *array = @[@"1",@"2",@"23",@"123"]; NSArray *aarray = [array sortedArrayUsingSelector:@selector(compare:)]; NSLog(@"aarray = %@",aarray); ``` 打印结果 ``` aarray = ( 1, 123, 2, 23 ) ``` ###2.sortedArrayUsingComparator 这个方法操作空间就比较大了，也是重点，一般用于数组元素对象的属性比较排序，首先看一下该方法的API文档： >NSArray *aarray = [arraysortUsingComparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) {code}]; 文中usingComparator后边，调取的是一个blok，返回的是枚举类型NSComparisonResult，该block决定了数组的排序方式。 ####两种写法： #####A.不调用compare方法 举个???? ``` NSMutableArray *array = [NSMutableArray arrayWithCapacity:10]; for (NSInteger i = 0; i < 4 ; i ++) { Person *per = [[Person alloc]init]; per.age = arc4random()%10 +1; NSLog(@"per =%ld",per.age); [array addObject:per]; } NSArray *aarray = [array sortedArrayUsingComparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) { Person *per1 = obj1; Person *per2 = obj2; if (per1.age > per2.age) { //降序 return NSOrderedAscending; //升序 // return NSOrderedDescending; }else if (per1.age < per2.age){ //升序 // return NSOrderedAscending; //降序 return NSOrderedDescending; }else{ return NSOrderedSame; } }]; for (Person *per in aarray) { NSLog(@"== %ld",per.age); } ``` 打印结果： ``` 2018-02-26 17:48:18.051843+0800 comandLine[2527:1303915] per =2 2018-02-26 17:48:18.052047+0800 comandLine[2527:1303915] per =6 2018-02-26 17:48:18.052060+0800 comandLine[2527:1303915] per =5 2018-02-26 17:48:18.052070+0800 comandLine[2527:1303915] per =5 2018-02-26 17:48:18.052126+0800 comandLine[2527:1303915] == 6 2018-02-26 17:48:18.052137+0800 comandLine[2527:1303915] == 5 2018-02-26 17:48:18.052146+0800 comandLine[2527:1303915] == 5 2018-02-26 17:48:18.052155+0800 comandLine[2527:1303915] == 2 ``` #####A.调用compare方法 举个???? ``` NSMutableArray *array = [NSMutableArray arrayWithCapacity:10]; for (NSInteger i = 0; i < 4 ; i ++) { Person *per = [[Person alloc]init]; per.age = arc4random()%10 +1; NSLog(@"per =%ld",per.age); [array addObject:per]; } NSArray *aarray = [array sortedArrayUsingComparator:^NSComparisonResult(id _Nonnull obj1, id _Nonnull obj2) { Person *per1 = obj1; Person *per2 = obj2; //升序 return [@([per1 age]) compare:@([per2 age])]; //降序 // return -[@([per1 age]) compare:@([per2 age])]; }]; for (Person *per in aarray) { NSLog(@"== %ld",per.age); } ``` 打印结果 ``` 2018-02-26 17:50:14.930696+0800 comandLine[2573:1314917] per =9 2018-02-26 17:50:14.930995+0800 comandLine[2573:1314917] per =1 2018-02-26 17:50:14.931013+0800 comandLine[2573:1314917] per =9 2018-02-26 17:50:14.931031+0800 comandLine[2573:1314917] per =10 2018-02-26 17:50:14.931149+0800 comandLine[2573:1314917] == 1 2018-02-26 17:50:14.931161+0800 comandLine[2573:1314917] == 9 2018-02-26 17:50:14.931167+0800 comandLine[2573:1314917] == 9 2018-02-26 17:50:14.931172+0800 comandLine[2573:1314917] == 10 ```             >###友情链接: >####[技术博客](http://www.cnblogs.com/tig666666/) [        简书主页](https://www.jianshu.com/u/707f27c59af4)