直接上代码 输出结果也在相应的代码里标注出来了

1 //main.m文件 2 #import 
     
       3 #import "Student.h" 4  5 int main(int argc, const char * argv[]) { 6     @autoreleasepool { 7          8         NSMutableArray 
      
        *_studentArrM; 9         NSMutableArray 
       
         *_studentArrMTest;10         11         _studentArrM = [NSMutableArray array];12         _studentArrMTest = [NSMutableArray array];13         14         Student *s1 = [Student studentWithNum:001 chinese:90.0 math:96.0 english:100.0];15         Student *s2 = [Student studentWithNum:002 chinese:90.0 math:100.0 english:96.0];16         Student *s3 = [Student studentWithNum:003 chinese:100.0 math:90.0 english:96.0];17         18         [_studentArrM addObject:s1];19         [_studentArrM addObject:s2];20         [_studentArrM addObject:s3];21         22         double mathAvg = [[_studentArrM valueForKeyPath:@"@avg.math"]doubleValue];23         double mathMax = [[_studentArrM valueForKeyPath:@"@max.math"]doubleValue];24         double mathMin = [[_studentArrM valueForKeyPath:@"@min.math"]doubleValue];25         double mathSum = [[_studentArrM valueForKeyPath:@"@sum.math"]doubleValue];26         NSLog(@"数学平均分%f 数学最高分%f 数学最低分%f 所有人的数学总分%f",mathAvg,mathMax,mathMin,mathSum);27         28         /*29          输出的内容为：数学平均分95.333333 数学最高分100.000000 数学最低分90.000000 所有人的数学总分286.00000030          31          提示：有兴趣的话可以自己多测试几组数据32          */33         34         //接下来试着处理一下数组中的对象的是否有重复的问题35         //测试需要我们可以再次给可变数组添加一个重复的对象36         [_studentArrM addObject:s2];37         [_studentArrM addObject:s2];38         39         NSArray *arrDistinct = [_studentArrM valueForKeyPath:@"@distinctUnionOfObjects.num"];40         NSArray *arrUnion = [_studentArrM valueForKeyPath:@"@unionOfObjects.num"];41         42         NSLog(@"DistinctArray %@ \n UnionArray %@",arrDistinct,arrUnion);43         /*44          输出的内容为：45          DistinctArray (46          3,47          2,48          149          )//提示：没有重复的所有值50          UnionArray (51          1,52          2,53          3,54          2,55          256          )//提示：有重复的所有值57          */58         59         //为了处理 多个数组 中的重复值的情况再次添加一个一个对象到测试数组60         [_studentArrMTest addObject:s2];61         62         NSLog(@"%@",[@[_studentArrM,_studentArrMTest] valueForKeyPath:@"@distinctUnionOfArrays.num"]);63         NSLog(@"%@",[@[_studentArrM,_studentArrMTest] valueForKeyPath:@"@unionOfArrays.num"]);64         /*65          输出的内容为66          (3,67          2,68          169          )//提示：没有重复的所有值70          71          (1,72          2,73          3,74          2,75          2,76          277          )//提示：有重复的所有值78          79          */80     }81     return 0;82 }
       
      
     

 

//Student.h文件 #import 
      
       @interface Student : NSObject/** 学号 */@property (nonatomic,assign)int num;/** 语文成绩 */@property (nonatomic,assign)double chinese;/** 语文成绩 */@property (nonatomic,assign)double math;/** 语文成绩 */@property (nonatomic,assign)double english;- (instancetype)initWithNum:(int)num chinese:(double)chinese math:(double)math english:(double)english;+ (instancetype)studentWithNum:(int)num chinese:(double)chinese math:(double)math english:(double)english;
      

1 //Student.m文件 2 #import "Student.h" 3  4 @implementation Student 5  6 - (instancetype)initWithNum:(int)num chinese:(double)chinese math:(double)math english:(double)english{ 7      8     self = [super init]; 9     if(self){10         _num = num;11         _chinese = chinese;12         _math = math;13         _english = english;14     }15     return self;16     17     18     19 }20 21 22 + (instancetype)studentWithNum:(int)num chinese:(double)chinese math:(double)math english:(double)english{23     24     return [[Student alloc]initWithNum:num chinese:chinese math:math english:english];25     26 }27 28 @end