ios 排序匯總
IOS幾種簡單有效的數組排序方法
//第一種，利用數組的sortedArrayUsingComparator調用 NSComparator ，obj1和obj2指的數組中的對象
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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;
};
NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"15",@"12",@"20",@"28",@"",nil];
//排序前
NSMutableString *outputBefore = [[NSMutableString alloc] init];
for(NSString *str in sortArray){
[outputBefore appendFormat:@"];
}
NSLog(@"排序前:%@",outputBefore);
[outputBefore release];
//第一種排序
NSArray *array = [sortArray sortedArrayUsingComparator:cmptr];
NSMutableString *outputAfter = [[NSMutableString alloc] init];
for(NSString *str in array){
[outputAfter appendFormat:@"];
}
NSLog(@"排序後:%@",outputAfter);
[outputAfter release];
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;
};
NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"15",@"12",@"20",@"28",@"",nil];
//排序前
NSMutableString *outputBefore = [[NSMutableString alloc] init];
for(NSString *str in sortArray){
[outputBefore appendFormat:@"];
}
NSLog(@"排序前:%@",outputBefore);
[outputBefore release];
//第一種排序
NSArray *array = [sortArray sortedArrayUsingComparator:cmptr];
NSMutableString *outputAfter = [[NSMutableString alloc] init];
for(NSString *str in array){
[outputAfter appendFormat:@"];
}
NSLog(@"排序後:%@",outputAfter);
[outputAfter release];
第二種 排序方法 利用sortedArrayUsingFunction 調用 對應方法customSort，這個方法中的obj1和obj2分別是指數組中的對象。
[plain]
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;
}
NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"15",@"12",@"20",@"28",@"",nil];
//排序前
NSMutableString *outputBefore = [[NSMutableString alloc] init];
for(NSString *str in sortArray){
[outputBefore appendFormat:@"];
}
NSLog(@"排序前:%@",outputBefore);
[outputBefore release];
NSArray *array = [sortArray sortedArrayUsingFunction:customSort context:nil];
NSMutableString *outputAfter = [[NSMutableString alloc] init];
for(NSString *str in array){
[outputAfter appendFormat:@"];
}
NSLog(@"排序後:%@",outputAfter);
[outputAfter release];
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;
}
NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"15",@"12",@"20",@"28",@"",nil];
//排序前
NSMutableString *outputBefore = [[NSMutableString alloc] init];
for(NSString *str in sortArray){
[outputBefore appendFormat:@"];
}
NSLog(@"排序前:%@",outputBefore);
[outputBefore release];
NSArray *array = [sortArray sortedArrayUsingFunction:customSort context:nil];
NSMutableString *outputAfter = [[NSMutableString alloc] init];
for(NSString *str in array){
[outputAfter appendFormat:@"];
}
NSLog(@"排序後:%@",outputAfter);
[outputAfter release];
第三種 利用sortUsingDescriptors調用NSSortDescriptor
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NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"price" ascending:NO];//其中，price為數組中的對象的屬性，這個針對數組中存放對象比較更簡潔方便
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:&sortDescriptor count:1];
[_totalInfoArray sortUsingDescriptors:sortDescriptors];
[_airListView refreshTable:_totalInfoArray];
[sortDescriptor release];
[sortDescriptors release];
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"price" ascending:NO];//其中，price為數組中的對象的屬性，這個針對數組中存放對象比較更簡潔方便
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:&sortDescriptor count:1];
[_totalInfoArray sortUsingDescriptors:sortDescriptors];
[_airListView refreshTable:_totalInfoArray];
[sortDescriptor release];
[sortDescriptors release];
20120619更新
排序操作，NSArray提供了很多種方法，按照所利用的排序參數，可以簡單分為descriptor,selector,function,和block排序。
數組排序的時候有sortedArrayUsingComparator方法，這裡的參數為NSComparator,這個類其實是Block所定義的
typedef NSComparisonResult (^NSComparator)(id obj1,id obj2);
所以我們直接用NSComparator myComparator=^(id obj1,id obj2){};
Block其實可以看作JS裡面的(){}();方法以及.Net中的匿名方法，即不需要聲明就直接使用的方法，主要用處包括回調、事件處理和排序。聲明和實現可以分開，也可以寫在一起：
[plain] view plaincopyprint?NSInteger (^blockExample)(int,NSString*)=^(int i,NSString *s)
{
NSLog(@"%d,%@",i,s);
};
blockExample(42,@"hello");
NSInteger (^blockExample)(int,NSString*)=^(int i,NSString *s)
{
NSLog(@"%d,%@",i,s);
};
blockExample(42,@"hello");
對於NSArray排序或者其他需要Block作為參數的函數來說，可以寫成下面兩種形式:
//聲明和使用
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NSComparison ( ^ageComparator )( id, id ) = ^( id o1, id o2 ) {
// 比較函數的實現
};
NSArray* objs_sortedByComparator = [objs sortedArrayUsingComparator:ageComparator];
// 不聲明，徹底匿名使用
NSArray* objs_sortedByComparator = [objs sortedArrayUsingComparator:^( id o1, id o2 ) { //...
}];
NSComparison ( ^ageComparator )( id, id ) = ^( id o1, id o2 ) {
// 比較函數的實現
};
NSArray* objs_sortedByComparator = [objs sortedArrayUsingComparator:ageComparator];
// 不聲明，徹底匿名使用
NSArray* objs_sortedByComparator = [objs sortedArrayUsingComparator:^( id o1, id o2 ) { //...
}];
例子：
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NSArray *array = [NSArray arrayWithObjects:@"71", @"16", @"51", @"104", @"13",@"2",@"1", nil];
array = [array sortedArrayUsingComparator:(NSComparator)^(id obj1, id obj2) {
return (arc4random() % 3) - 1;
}];
// NSLog(@"array:%@", array);
NSArray *sortedArray = [array sortedArrayUsingComparator: ^(id obj1, id obj2) {
if ([obj1 integerValue] > [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedAscending;
}
if ([obj1 integerValue] < [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedDescending;
}
return (NSComparisonResult)NSOrderedSame;
}];
sortedArray 是排好序的時間對象數組
// 按時間排序
NSArray *sortedArray = [srcArrary sortedArrayUsingComparator:^(id obj1, id obj2)
{
NSComparisonResult result = [obj1 compare:obj2];
switch(result)
{
case NSOrderedAscending:
return NSOrderedDescending;
case NSOrderedDescending:
return NSOrderedAscending;
case NSOrderedSame:
return NSOrderedSame;
default:
return NSOrderedSame;
} // 時間從近到遠（遠近相對當前時間而言）
}];
NSArray *array = [NSArray arrayWithObjects:@"71", @"16", @"51", @"104", @"13",@"2",@"1", nil];
array = [array sortedArrayUsingComparator:(NSComparator)^(id obj1, id obj2) {
return (arc4random() % 3) - 1;
}];
// NSLog(@"array:%@", array);
NSArray *sortedArray = [array sortedArrayUsingComparator: ^(id obj1, id obj2) {
if ([obj1 integerValue] > [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedAscending;
}
if ([obj1 integerValue] < [obj2 integerValue]) {
return (NSComparisonResult)NSOrderedDescending;
}
return (NSComparisonResult)NSOrderedSame;
}];
sortedArray 是排好序的時間對象數組
// 按時間排序
NSArray *sortedArray = [srcArrary sortedArrayUsingComparator:^(id obj1, id obj2)
{
NSComparisonResult result = [obj1 compare:obj2];
switch(result)
{
case NSOrderedAscending:
return NSOrderedDescending;
case NSOrderedDescending:
return NSOrderedAscending;
case NSOrderedSame:
return NSOrderedSame;
default:
return NSOrderedSame;
} // 時間從近到遠（遠近相對當前時間而言）
}];
//隨機排序
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NSArray *array = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", @"5", nil];
array = [array sortedArrayUsingComparator:(NSComparator)^(id obj1, id obj2) {
return (arc4random() % 3) - 1;
}];
NSLog(@"array:%@", array);
NSArray *array = [NSArray arrayWithObjects:@"1", @"2", @"3", @"4", @"5", nil];
array = [array sortedArrayUsingComparator:(NSComparator)^(id obj1, id obj2) {
return (arc4random() % 3) - 1;
}];
NSLog(@"array:%@", array);
