[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