Object-C排序的几种方法

方法一
利用系统自带的排序方法:

- (NSArray<ObjectType> *)sortedArrayUsingSelector:(SEL)comparator;  NSArray *array = [NSArray arrayWithObjects:@"1",@"9",@"3",@"4",@"2", nil];  array = [array sortedArrayUsingSelector:@selector(compare:)];//系统自带  NSLog(@"%@",array);  注意:也可以重写compare:方法如下所示  **方法二 自定义方法，用选择器（类似于C语言的回调函数）进行排序**  Person.m@implementation Person+(Person *)personWithName:(NSString *)name age:(int)age{    Person *p = [[Person alloc]init];    p.age = age;    p.name = name;    return p;}-( NSComparisonResult)comparePerson:(Person *)p{    NSComparisonResult re = [[NSNumber numberWithInt:[p age]] compare:[NSNumber numberWithInt:[self age]]];    if (re == NSOrderedSame) {        re = [self.name compare:p.name];    }    return re;}-(void) sortArray2{    Person *p1 = [Person personWithName:@"zhangsan" age:12];    Person *p2 = [Person personWithName:@"zhangen" age:12];    Person *p3 = [Person personWithName:@"zhangat" age:12];    Person *p4 = [Person personWithName:@"zhangsrg" age:12];    NSArray *array = [NSArray arrayWithObjects:p1,p2,p3,p4, nil];    NSArray *sortedArray = [array sortedArrayUsingSelector:@selector(comparePerson:)];    NSLog(@"排序后:%@",sortedArray);}- (NSString *)description{    return [NSString stringWithFormat:@"%@,%d", self.name,self.age];}@end

方法三 利用Block进行排序

 NSArray *array = [NSArray arrayWithObjects:@"1",@"9",@"3",@"4",@"2", nil];        NSComparator res = ^(id obj1, id obj2){            return [obj1 compare:obj2];//直接比较//            if ([obj1 integerValue] > [obj2 integerValue]) {// 转换成整型值，在进行比较//                return -1L;//            }else//                return 1L;        };        array = [array sortedArrayUsingComparator:res];        NSLog(@"%@",array);

方法四 高级排序
person.m

#import "Person.h"#import "Car.h"@implementation Person+(Person *)personWithName:(NSString *)name age:(int)age{    Person *p = [[Person alloc]init];    p.age = age;    p.name = name;    return p;}-(instancetype)initWithName:(NSString *)name age:(int)age car:(Car *)car{    if (self = [super init]) {        self.name = name;        self.age =age;        self.car = car;    }    return self;}- (NSString *)description{    return [NSString stringWithFormat:@"%@,%d,%@", self.name,self.age,self.car];}-(void) sortArray2{    Car * c1= [[Car alloc]initWitnName:@"1"];    Car * c2= [[Car alloc]initWitnName:@"2"];    Car * c3= [[Car alloc]initWitnName:@"3"];    Car * c4= [[Car alloc]initWitnName:@"4"];    Person *p1 = [[Person alloc]initWithName:@"z"age:34 car:c1];    Person *p2 = [[Person alloc]initWithName:@"r" age:12 car:c2];    Person *p3 = [[Person alloc]initWithName:@"a" age:17 car:c3];    Person *p4 = [[Person alloc]initWithName:@"c"age:87 car:c4];    NSArray *array = [NSArray arrayWithObjects:p1,p2,p3,p4, nil];    //构建排序描述器    NSSortDescriptor *carNameDesc = [NSSortDescriptor sortDescriptorWithKey:@"car.name" ascending:YES];   // NSSortDescriptor *personNameDesc = [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES];   // NSSortDescriptor *personAgeDesc = [NSSortDescriptor sortDescriptorWithKey:@"age" ascending:YES];   // NSArray *descriptorArray = [NSArray arrayWithObjects:personAgeDesc, nil];//结果(按年龄排序1)     // NSArray *descriptorArray = [NSArray arrayWithObjects:personNameDesc, nil];// 结果(按人的名字排序2)            NSArray *descriptorArray = [NSArray arrayWithObjects:carNameDesc, nil];// 结果(按car的名字排序3)    NSArray *sortedArray = [array sortedArrayUsingDescriptors: descriptorArray];    NSLog(@"%@",sortedArray);}@end

Car.m

#import "Car.h"@implementation Car-(instancetype)initWitnName:(NSString *)name{    if (self = [super init]) {        self.name = name;    }    return self;}- (NSString *)description{    return [NSString stringWithFormat:@"%@", self.name];}@end

结果(按年龄排序1)

结果(按人的名字排序2)

结果(按car的名字排序3)