數組排序

時間 2019-11-17

標籤數組排序简体版

原文原文鏈接

 1 #pragma mark 冒泡排序
 2 - (void)userArrSort:(NSMutableArray *)userArr
 3 {
 4     int n = userArr.count;
 5     int i,j;
 6     NSDictionary *temp;
 7     for(j=0;j<n-1;j++)
 8     {
 9         for(i=0;i<n-1-j;i++)
10         {
11 //            NSDictionary*ssy = [];
12             if(((NSString *)[userArr[i] objectForKey:@"vlevel"]).intValue<((NSString *)[userArr[i+1] objectForKey:@"vlevel"]).intValue)//數組元素大小按升序排列
13             {
14                 temp=userArr[i];
15                 userArr[i]=userArr[i+1];
16                 userArr[i+1]=temp;
17             }
18         }
19     }
20     for (int x = 0; x<userArr.count; x++)
21     {
22         if (1) {
23 //            [userArr replaceObjectAtIndex:0 withObject:[userArr[i]];
24         }
25     }
26 }
27 #pragma mark 已排序數組插入一條數據
28 - (void)insertObjectInUserArr:(NSMutableArray *)userArr withobject:(NSDictionary *)dic
29 {
30     int j;
31     if(((NSString *)[dic objectForKey:@"vlevel"]).intValue<=((NSString *)[userArr[userArr.count - 1] objectForKey:@"vlevel"]).intValue)
32     {
33         [userArr insertObject:dic atIndex:userArr.count];
34     }else
35     {
36         for(int i=0;i<userArr.count;i++)
37         {
38             if(((NSString *)[dic objectForKey:@"vlevel"]).intValue>((NSString *)[userArr[i] objectForKey:@"vlevel"]).intValue)
39             {
40                 j = i;
41                 [userArr insertObject:dic atIndex:j];
42                 break;
43             }
44         }
45     }
46 
47 
48 }

（1）直接調用系統的方法排序int數組

NSMutableArray*array = [[NSMutableArrayalloc]init];xcode

[arrayaddObject:[NSNumbernumberWithInt:20]];app

[arrayaddObject:[NSNumbernumberWithInt:1]];less

[arrayaddObject:[NSNumbernumberWithInt:4]];oop

NSArray*sortedArray = [arraysortedArrayUsingSelector:@selector(compare:)];spa

for(inti =0; i < [sortedArraycount]; i++).net

{code

intx = [[sortedArrayobjectAtIndex:i]intValue];對象

NSLog(@"######%d\n", x);blog

}

（2）用descriptor方法

#import<Cocoa/Cocoa.h>

@interfaceNode: NSObject {

intx;

inty;

intv;

}

@property intx;

@property inty;

@property intv;

- (id)init:(int)tx y:(int)ty v:(int)tv;

@end

@implementationNode

@synthesizex;

@synthesizey;

@synthesizev;

- (id)init:(int)tx y:(int)ty v:(int)tv {

x= tx;

y= ty;

v= tv;

return self;

}

@end

intmain(intargc,char*argv[])

{

NSMutableArray *myMutableArray = [[NSMutableArrayalloc]init];

Node *n[2];

n[0] = [[Nodealloc]init:2y:1v:1];

n[1] = [[Nodealloc]init:4y:2v:2];

[myMutableArrayaddObject:n[0]];

[myMutableArrayaddObject:n[1]];

NSSortDescriptor* sortByA = [NSSortDescriptorsortDescriptorWithKey:@"x"ascending:NO];

[myMutableArraysortUsingDescriptors:[NSArrayarrayWithObject:sortByA]];

for(Node*tinmyMutableArray) {

NSLog(@"x === %d", t.x);

NSLog(@"y === %d", t.y);

NSLog(@"v === %d", t.v);

}

（3）自定義重寫方法

Abstract:Constants returned by comparison functions, indicating whether a value is equal to, less than, or greater than another value.

Declaration:enumCFComparisonResult{

kCFCompareLessThan= -1,

kCFCompareEqualTo= 0,

kCFCompareGreaterThan= 1

};

#import<Cocoa/Cocoa.h>

@implementation NSNumber (MySort)

- (NSComparisonResult) myCompare:(NSString *)other {

//這裏能夠做適當的修正後再比較

int result = ([selfintValue]>>1) - ([other intValue]>>1);

//這裏能夠控制排序的順序和逆序

return result < 0 ?NSOrderedDescending : result >0 ?NSOrderedAscending :NSOrderedSame;

}

@end

int main(int argc, char *argv[])

{

NSMutableArray *array = [[NSMutableArrayalloc]init];

[arrayaddObject:[NSNumbernumberWithInt:20]];

[arrayaddObject:[NSNumbernumberWithInt:1]];

[arrayaddObject:[NSNumbernumberWithInt:4]];

NSArray *sortedArray = [arraysortedArrayUsingSelector:@selector(myCompare:)];

for(int i = 0; i < [sortedArraycount]; i++)

{

int x = [[sortedArrayobjectAtIndex:i]intValue];

NSLog(@"######%d\n", x);

}

c語言實現的學生成績管理系統是面向過程的,而OC實現的學生成績管理系統則是面向對象的.

對該系統的重難點講述以下:

1.排序.系統中的四個關鍵字分別是 stuID,姓名,年齡,成績.咱們能夠選擇這四種方式並選擇升降序的方法進行排序.

系統中使用的是 NSmutableArray 存儲數據.那麼如何對對象是類成員的數組排序呢?

先看看NSMutableArray排序的幾種方式.

1)使用@Seletor選擇器調用方法排序.