OC NSArray数组排序

一、一般排序

         // 排序
         NSArray *arr = @[@"",@"",@"",@""];
         NSArray *newarr = [arr sortedArrayUsingSelector:@selector(compare:)];
         NSLog(@"%@",newarr);

二、高级排序（数组中存的是对象，按对象的属性进行排序）

 #import <Foundation/Foundation.h>

 @interface Student : NSObject

 @property (assign ,nonatomic) int age;

 //提供一种比较方式
 - (NSComparisonResult)compareStudentWithAge:(Student *)tempStudent;

 @end

 #import "Student.h"

 @implementation Student

 - (NSComparisonResult)compareStudentWithAge:(Student *)tempStudent
 {
　　　//方法1：

//    　　NSNumber *num1 = [[NSNumber alloc] initWithInteger:self.age];

//    　　NSNumber *num2 = [[NSNumber alloc] initWithInteger:tempStudent.age];

//    　　return [num1 compare:num2];

　　　　//方法2：
     if (self.age>tempStudent.age) {
         return NSOrderedDescending;
     }
     else if (self.age<tempStudent.age)
         return NSOrderedAscending;
     else
         return NSOrderedSame;
 }

 -(NSString *)description
 {
     return [NSString stringWithFormat:@"age:%d",self.age];
 }

 @end

 #import <Foundation/Foundation.h>

 #import "Student.h"
 int main(int argc, const char * argv[]) {
     @autoreleasepool {

         Student *stu1 = [[Student alloc] init];
         stu1.age= ;
         Student *stu2 = [[Student alloc] init];
         stu2.age= ;
         Student *stu3 = [[Student alloc] init];
         stu3.age= ;

         NSArray *stuArr = @[stu1,stu2,stu3];
         NSArray *newStuArr = [stuArr sortedArrayUsingSelector:@selector(compareStudentWithAge:)];
         NSLog(@"%@",newStuArr);
 }
 return ;
 }

三、超级排序（数组中对象多属性）

 #import <Foundation/Foundation.h>

 @interface People : NSObject

 @property (assign,nonatomic) NSInteger age;
 @property (assign, nonatomic) NSInteger score;
 @property (copy,nonatomic) NSString *name;

 @end

 #import "People.h"

 @implementation People

 - (NSString *)description
 {
     return [NSString stringWithFormat:@"age:%ld score:%ld name:%@", self.age,self.score,self.name];
 }

 #import <Foundation/Foundation.h>
 #import "People.h"

 int main(int argc, const char * argv[]) {
     @autoreleasepool {

         People *stu1 = [[People alloc] init];
         stu1.age = ;
         stu1.score = ;
         stu1.name = @"bowen1";

         People *stu2 = [[People alloc] init];
         stu2.age = ;
         stu2.score = ;
         stu2.name = @"bowen2";

         People *stu3 = [[People alloc] init];
         stu3.age = ;
         stu3.score = ;
         stu3.name = @"bowen3";

         People *stu4 = [[People alloc] init];
         stu4.age = ;
         stu4.score = ;
         stu4.name = @"bowen4";

         People *stu5 = [[People alloc] init];
         stu5.age = ;
         stu5.score = ;
         stu5.name = @"bowen5";

         NSArray *arr = @[stu1,stu2,stu3,stu4,stu5];

         // 排序描述，数组按属性排序 NSSortDescriptor
         NSSortDescriptor *ageSort = [[NSSortDescriptor alloc] initWithKey:@"age" ascending:YES];
         NSSortDescriptor *scoreSort = [[NSSortDescriptor alloc] initWithKey:@"score" ascending:YES];
         NSSortDescriptor *nameScort = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];

         //使用[排序描述]对数组进行排序
         NSArray *newArr = [arr sortedArrayUsingDescriptors:@[ageSort,scoreSort,nameScort]];

         NSLog(@"%@",newArr);

     }
     return ;
 }

 @end