[Object C]_[初级]_[NSArray排序]

场景：根据需求让数据内的元素有序排列。

下面是具体实例说明。

ArrayObject.h

#import <Foundation/Foundation.h>@interface Person : NSObject{    NSString  *_name;        NSInteger  _age;}@property (readwrite, copy) NSString  *_name;@property (readwrite, assign) NSInteger  _age;@end@interface ArrayObject : NSObject-(void)testSortedArrayUsingComparater;-(void) testSortArrayUsingSelector;-(void) testSortedArrayUsingFunction;-(void) doTestSortUsingDescriptors;@end

ArrayObject.m

#import "ArrayObject.h"@implementation Person@synthesize _name;@synthesize  _age;- (void)dealloc{    [_name release];        [super dealloc];}@end@implementation ArrayObject//第一种，利用数组的sortedArrayUsingComparator调用 NSComparator ，obj1和obj2指的数组中的对象NSComparator cmptr = ^(id obj1, id obj2){    if ([obj1 integerValue] > [obj2 integerValue]) {        return (NSComparisonResult)NSOrderedDescending;    }        if ([obj1 integerValue] < [obj2 integerValue]) {        return (NSComparisonResult)NSOrderedAscending;    }    return (NSComparisonResult)NSOrderedSame;};-(void)testSortedArrayUsingComparater{    NSArray *sortArray = [[NSArray alloc] initWithObjects:@"10",@"13",@"5",@"15",@"8",@"20",@"1",@"5",@"3",@"7",@"45",@"4",@"23",@"",nil];    //排序前    NSMutableString *beforeStr = [NSMutableString new];    for(NSString *str in sortArray)    {        [beforeStr appendFormat:@"%@ ",str];    }     NSLog(@"排序前:%@",beforeStr);     [beforeStr release];     //第一种排序     NSArray *array = [sortArray sortedArrayUsingComparator:cmptr];          NSMutableString *afterStr = [NSMutableString new];     for(NSString *str in array){         [afterStr appendFormat:@"%@ ",str];      }      NSLog(@"排序后:%@",afterStr);      [afterStr release];}

输出结果：

//第二种排序算法 利用sortedArrayUsingSelector调用系统定义的compare:,主要是对字符串的比较

-(void) testSortArrayUsingSelector{    NSArray *sortArray = [[NSArray alloc] initWithObjects:@"10",@"13",@"5",@"15",@"8",@"20",@"1",@"5",@"3",@"7",@"45",@"4",@"23",@"",nil];    //排序前     NSMutableString *beforeStr = [NSMutableString new];    for(NSString *str in sortArray)    {        [beforeStr appendFormat:@"%@ ",str];    }    NSLog(@"排序前:%@",beforeStr);    [beforeStr release];    //第一种排序    //- (NSComparisonResult)compare:(NSString *)string;//比较字符串的大小    //- (NSComparisonResult)compare:(NSString *)string options:(NSStringCompareOptions)mask; 比较字符串,按mask的参数进行比较   //mask 参数可以是: NSCaseInsensitiveSearch, NSLiteralSearch, NSNumericSearch.        NSArray *array =[sortArray sortedArrayUsingSelector:@selector(compare:options:)];         NSMutableString *affterStr = [NSMutableString new];    for(NSString *str in array){        [affterStr appendFormat:@"%@ ",str];    }    NSLog(@"排序后:%@",affterStr);    [affterStr release];}

输出结果：

若把

NSArray *array =[sortArray sortedArrayUsingSelector:@selector(compare:options:)];中<pre name="code" class="objc">compare:options:改为compare:，则输出结果为：

//第三种 排序方法 利用sortedArrayUsingFunction 调用 对应方法customSort，这个方法中的obj1和obj2分别是指数组中的对象。

NSInteger customSort(id obj1, id obj2,void* context){    if ([obj1 integerValue] > [obj2 integerValue]) {        return (NSComparisonResult)NSOrderedDescending;    }        if ([obj1 integerValue] < [obj2 integerValue]) {        return (NSComparisonResult)NSOrderedAscending;    }    return (NSComparisonResult)NSOrderedSame;}-(void) testSortedArrayUsingFunction{    NSArray *sortArray = [[NSArray alloc] initWithObjects:@"10",@"13",@"5",@"15",@"8",@"20",@"1",@"5",@"3",@"7",@"45",@"4",@"23",@"",nil];    //排序前    NSMutableString *beforeStr = [NSMutableString new];    for(NSString *str in sortArray){    [beforeStr appendFormat:@"%@ ",str];     }     NSLog(@"排序前:%@",beforeStr);     [beforeStr release];          NSArray *array = [sortArray sortedArrayUsingFunction:customSort context:nil];          NSMutableString *afterStr = [NSMutableString new];     for(NSString *str in array){         [afterStr appendFormat:@"%@ ",str];          }      NSLog(@"排序后:%@",afterStr);      [afterStr release];}

输出结果：

//第四种 利用sortUsingDescriptors调用NSSortDescriptor

-(void) doTestSortUsingDescriptors{    Person *person1 = [[Person alloc] init];    [person1 set_name:@"ABCD"];    [person1 set_age:24];        Person *person2 = [[Person alloc] init];    [person2 set_name:@"ACBA"];    [person2 set_age:22];        Person *person3 = [[Person alloc] init];    [person3 set_name:@"ABDC"];    [person3 set_age:33];        NSMutableArray *array = [NSMutableArray arrayWithObjects:person1, person2, person3, nil];    [person1 release];    [person2 release];    [person3 release];    NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"_name" ascending:YES];//YES降序，NO升序    //这个数组保存的是排序好的对象    NSArray *tempArray = [array sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]];    for (Person *ii in tempArray) {         NSLog(@"name:%@,age:%ld",ii._name,ii._age);    }}@end

输出结果：

降序：ascending:YES

升序：ascending:NO

用数据结构排序算法对NSArray进行排序，项目代码点击链接下载：

http://download.csdn.net/detail/moqj_123/9252059