NSMutableArray中各種自定義排序方法
-(void) test2{
//宣告一個數組
NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"123",@"23",@"45",@"67", nil];
NSMutableString *outputBefor = [[NSMutableStringalloc] init];
for (NSString *str in sortArray) {
[outputBefor appendFormat:@"%@ ",str];
}
NSLog(@"排序前:%@",outputBefor);
NSArray *arr = [sortArray sortedArrayUsingComparator:^NSComparisonResult(id obj1,id obj2){
if ([obj1 integerValue] > [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedDescending;
}
if ([obj1 integerValue] < [obj2 integerValue]) {
return (NSComparisonResult)
}
return (NSComparisonResult)NSOrderedSame;
}];
}
/*
利用sortedArrayUsingFunction呼叫對應方法customSort
這個方法中的Obje1和obj2分別是指陣列中的物件
*/
SecondMethod.mNSInteger customSort(id obj1,id obj2){
if ([obj1 integerValue] > [obj2 integerValue]) {
return (NSComparisonResult
}
if ([obj1 integerValue] < [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
}
-(void)twotest1{
NSArray *sortArray = [[NSArray alloc] initWithObjects:@"325",@"4516",@"457",@"325", nil];
NSMutableString *outputBefor = [[NSMutableStringalloc] init];
for (NSString *str in sortArray) {
[outputBefor appendFormat:@"%@ ",str];
}
NSLog(@"排序前: %@",outputBefor);
NSArray *array = [sortArray sortedArrayUsingFunction:customSortcontext:nil];
NSMutableString *outputAfter = [[NSMutableStringalloc] init];
for (NSString *str in array) {
[outputAfter appendFormat:@"%@ ",str];
}
NSLog(@"排序後%@",outputAfter);
}
/*
利用sortUsingDescriptors呼叫NSSortDescriptor
我們以陣列的排序為例（也許NSSortDescriptor最常用的地方是NSFetchedResultsController中，但用法大致相同）。
假設要對userArray陣列中的物件進行排序，而陣列中含有多個User物件（User繼承於NSManagedObject），User中有一個屬性叫做country。
[plain]
1. NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"country" ascending:YES];
2. [userArray sortUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]];
這樣，就可以根據每一個User的country來進行升序或降序的排列，sortUsingDescriptors的引數是一個數組，也就是說可以使用多個排序引數。
再比如說，User有一個關係叫做image，image有個屬性叫做timestamp，如果要根據User的image關係的timestamp排序，僅需把上面程式碼中的country改為，image.timestamp。
*/
Score.h
@interface Score : NSObject
@property(nonatomic,assign)NSInteger score;
-(id)initWithScore:(NSInteger)score;
@end
Score.m
@implementation Score
-(id)initWithScore:(NSInteger)score{
self = [superself];
if (self) {
_score = score;
}
return self;
}
@end
Student.h
#include "Score.h"
@interface Student : NSObject
@property (nonatomic,copy)NSString *name;
@property(nonatomic,copy)Score *stuScore;
-(id)initWithName:(NSString *)name andScore:(NSInteger)score;
@end
Student.m
@implementation Student
-(id)initWithName:(NSString *)name andScore:(NSInteger)score{
self = [superself];
if (self) {
_name = name;
_stuScore = [[Score alloc] initWithScore:score];
}
return self;
}
@end
ThirdMethod.h@interface three : NSObject
-(void)sortedPrint;
@end
ThirdMethod.m@implementation three
-(void)sortedPrint{
NSMutableArray *array = [[NSMutableArrayalloc] init];
for (int i = 0; i < 9; i ++) {
NSInteger random = arc4random() % 21;
Student *stu = [[Student alloc] initWithName:@"luo" andScore:random];
[array addObject:stu];
}
NSLog(@"%@",array);
NSSortDescriptor *descriptor = [[NSSortDescriptoralloc] initWithKey:@"stuScore.score"ascending:YES];
[array sortUsingDescriptors:[NSArrayarrayWithObject:descriptor]];
NSLog(@"%@",array);
}
@end