Objective-c sort array int方法(附:comparison methods)

（1）直接调用系统的方法排序int

NSMutableArray *array = [[NSMutableArray alloc]init];

[array addObject:[NSNumber numberWithInt:20]];

[array addObject:[NSNumber numberWithInt:1]];

[array addObject:[NSNumber numberWithInt:4]];

NSArray *sortedArray = [array sortedArrayUsingSelector:@selector(compare:)];

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

{

int x = [[sortedArray objectAtIndex:i]intValue];

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

}

 

（2）用descriptor方法

#import <Cocoa/Cocoa.h>

 

@interface Node: NSObject {

int x;

int y;

int v;

}

 

@property int x;

@property int y;

@property int v;

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

@end

 

@implementation Node

 

@synthesize x;

@synthesize y;

@synthesize v;

 

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

x = tx;

y = ty;

v = tv;

return self;

}

 

@end

 

int main(int argc, char *argv[])

{

NSMutableArray *myMutableArray = [[NSMutableArray alloc]init];

Node *n[2];

n[0] = [[Node alloc]init:2 y:1 v:1];

n[1] = [[Node alloc]init:4 y:2 v:2];

 

[myMutableArray addObject:n[0]];

[myMutableArray addObject:n[1]];

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

[myMutableArray sortUsingDescriptors:[NSArray arrayWithObject:sortByA]];

for(Node *t in myMutableArray) {

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

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

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

}

}

 

 

（3）自定义重写方法

/*

 

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

Declaration: enum CFComparisonResult {

   kCFCompareLessThan = -1,

   kCFCompareEqualTo = 0,

   kCFCompareGreaterThan = 1

};

*/

#import <Cocoa/Cocoa.h>

@implementation NSNumber (MySort)

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

    //这里可以作适当的修正后再比较

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

    //这里可以控制排序的顺序和逆序

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

}

 

@end

int main(int argc, char *argv[])

{

NSMutableArray *array = [[NSMutableArray alloc]init];

[array addObject:[NSNumber numberWithInt:20]];

[array addObject:[NSNumber numberWithInt:1]];

[array addObject:[NSNumber numberWithInt:4]];

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

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

{

int x = [[sortedArray objectAtIndex:i]intValue];

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

}

}

 

注：

关于 sortedArrayUsingSelector:@selector(copare:)是默认的排序方法，而你自己可以重写排序方法，比如上面的myCompare

附：

search/find and comparison methods

enum {
    NSCaseInsensitiveSearch = 1,
    NSLiteralSearch = 2,        /* Exact character-by-character equivalence */
    NSBackwardsSearch = 4,        /* Search from end of source string */
    NSAnchoredSearch = 8,        /* Search is limited to start (or end, if NSBackwardsSearch) of source string */
    NSNumericSearch = 64        /* Added in 10.2; Numbers within strings are compared using numeric value, that is, Foo2.txt < Foo7.txt < Foo25.txt; only applies to compare methods, not find */
#if MAC_OS_X_VERSION_10_5 <= MAC_OS_X_VERSION_MAX_ALLOWED || __IPHONE_2_0 <= __IPHONE_OS_VERSION_MAX_ALLOWED
    ,
    NSDiacriticInsensitiveSearch = 128, /* If specified, ignores diacritics (o-umlaut == o) */
    NSWidthInsensitiveSearch = 256, /* If specified, ignores width differences ('a' == UFF41) */
    NSForcedOrderingSearch = 512 /* If specified, comparisons are forced to return either NSOrderedAscending or NSOrderedDescending if the strings are equivalent but not strictly equal, for stability when sorting (e.g. "aaa" > "AAA" with NSCaseInsensitiveSearch specified) */
#endif /* MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_5 */
#if MAC_OS_X_VERSION_10_7 <= MAC_OS_X_VERSION_MAX_ALLOWED || __IPHONE_3_2 <= __IPHONE_OS_VERSION_MAX_ALLOWED
    ,
    NSRegularExpressionSearch = 1024    /* Applies to rangeOfString:..., stringByReplacingOccurrencesOfString:..., and replaceOccurrencesOfString:... methods only; the search string is treated as an ICU-compatible regular expression; if set, no other options can apply except NSCaseInsensitiveSearch and NSAnchoredSearch */
#endif /* MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_7 || __IPHONE_3_2 <= __IPHONE_OS_VERSION_MAX_ALLOWED */
};