定義一個學生類，需要有姓名，年齡，考試成績三個成員屬性，建立5個物件，屬性可以任意值。（Objective-C）

1)    不使用@property，手動編寫他們的訪問器方法（getter和setter），注意記憶體管理（手動管理記憶體）

2)    增加一個便利構造器（快速構造器）

3)    使用NSLog輸出學生物件時，輸出資訊格式為：My Name Is XXX  Age Is XXX Score Is XXX

4)    對5個學生物件按照成績—》年齡—》姓名優先順序排序（成績相同按照年齡排序，成績年齡相同按照姓名排序（5個學生的屬性值自己隨便設定，姓名不考慮中文，按26個大小字母排序））

這是一道黑馬入學考試題，我做了3個小時，終於做好了這道題，涉及到了很多OC語言基礎的知識點，由於使用的是xocde6.3.2，沒有辦法進行手動記憶體管理，所以省略了這一部分，供大家參考

程式碼：

#import <Foundation/Foundation.h>

@interface Student : NSObject
{
    //姓名
    NSString* _name;
    //年齡
    int _age;
    //成績
    int _score;
}

-(void)setName:(NSString*)name;
-(void)setAge:(int)age;
-(void)setScore:(int)score;

-(NSString*)getName;
-(int)getAge;
-(int)getScore;

+(BOOL)isNameHigher:(NSString *)n1 and:(NSString *)n2;

//比較兩個學生的排名，是否第一個學生比第二個學生排名靠前
+(BOOL)isHigher:(Student*) student1 and:(Student*)student2;

-(id)initWithName:(NSString*)name andAge:(int)age andScore:(int)score;
@end
 

#import "Student.h"

@implementation Student

-(void)setName:(NSString *)name{
    _name = name;
}

-(void)setAge:(int)age{
    _age = age;
}

-(void)setScore:(int)score{
    _score = score;
}

-(NSString *)getName{
    return _name;
}

-(int)getAge{
    return _age;
}

-(int)getScore{
    return _score;
}


-(id)initWithName:(NSString *)name andAge:(int)age andScore:(int)score{
    if (self = [super init]) {
        _name = name;
        _age = age;
        _score = score;
    }
    return self;
}

-(NSString *)description{
//    return [NSString stringWithFormat:@"%@ %d %d",_name,_age,_score];
    return [NSString stringWithFormat:@"My name is %@ age is %d score is %d",_name,_age,_score];
}

+(BOOL)isNameHigher:(NSString *)n1 and:(NSString *)n2{
    unsigned long time;
    if ([n1 length]>[n2 length]) {
        time = [n2 length];
    }else{
        time = [n1 length];
    }
    for (int i = 0; i<time; i++) {
        if ([n1 characterAtIndex:i]<[n2 characterAtIndex:i]) {
            return YES;
        }else if ([n1 characterAtIndex:i]>[n2 characterAtIndex:i]){
            return NO;
        }
    }
    NSLog(@"所有條件都相同，根據姓名長度比較");
    return [n1 length]<[n2 length];
}

+(BOOL)isHigher:(Student*) student1 and:(Student*)student2{
    //比較兩個學生的分數，分數高的返回
    if ([student1 getScore] > [student2 getScore]) {
        return YES;
    }else if ([student1 getScore] < [student2 getScore]){
        return NO;
    }else {//如果兩個學生的分數相同，比較兩個學生的年齡，年齡低的返回
        if ([student1 getAge] < [student2 getAge]) {
            return YES;
        }else if ([student1 getAge] > [student2 getAge]){
            return NO;
        }else{
            //如果兩個學生的分數和年齡都相同，根據姓名（限制為英文）前端字母排序
            NSString* n1 = [[student1 getName] lowercaseString];
            NSString* n2 = [[student2 getName] lowercaseString];
            if ([self isNameHigher:n1 and:n2]){
                return YES;
            }else{
                return NO;
            }
        }
    }
}
@end
 

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

int main(){
    
    Student* s1 = [[Student alloc]initWithName:@"Tim" andAge:11 andScore:79];
    Student* s2 = [[Student alloc]initWithName:@"Calo" andAge:12 andScore:86];
    Student* s3 = [[Student alloc]initWithName:@"QaJin" andAge:14 andScore:95];
    Student* s4 = [[Student alloc]initWithName:@"Jaren" andAge:11 andScore:95];
    Student* s5 = [[Student alloc]initWithName:@"Jare" andAge:11 andScore:95];
    
    NSMutableArray* students = [NSMutableArray arrayWithObjects:s1,s2,s3,s4,s5, nil];
    
    NSUInteger count = [students count];
    
    //使用氣泡排序對可變集合（學生集合）進行排序
    for (int i = 0; i<count; i++) {
        for (int j = 0; j<count; j++) {
            if (j<count-1 && ![Student isHigher:students[j] and:students[j+1]]) {
                Student* s =students[j];
                [students setObject:students[j+1] atIndexedSubscript:j];
                [students setObject:s atIndexedSubscript:j+1];
            }
        }
    }
    
    NSLog(@"%@",students);
    return 0;
}