ios 排序汇总
- ios 排序汇总
-
IOS几种简单有效的数组排序方法
//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;
};
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];
//第一种排序
NSArray *array = [sortArray sortedArrayUsingComparator:cmptr];
NSMutableString *outputAfter = [[NSMutableString alloc] init];
for(NSString *str in array){
[outputAfter appendFormat:@"];
}
NSLog(@"排序后:%@",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];
//第一种排序
NSArray *array = [sortArray sortedArrayUsingComparator:cmptr];
NSMutableString *outputAfter = [[NSMutableString alloc] init];
for(NSString *str in array){
[outputAfter appendFormat:@"];
}
NSLog(@"排序后:%@",outputAfter);
[outputAfter release];第二种 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。
[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(@"排序后:%@",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(@"排序后:%@",outputAfter);
[outputAfter release];第三种 利用sortUsingDescriptors调用NSSortDescriptor
[plain]
NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"price" ascending:NO];//其中,price为数组中的对象的属性,这个针对数组中存放对象比较更简洁方便
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为数组中的对象的属性,这个针对数组中存放对象比较更简洁方便
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提供了很多种方法,按照所利用的排序参数,可以简单分为descriptor,selector,function,和block排序。
数组排序的时候有sortedArrayUsingComparator方法,这里的参数为NSComparator,这个类其实是Block所定义的
typedef NSComparisonResult (^NSComparator)(id obj1,id obj2);
所以我们直接用NSComparator myComparator=^(id obj1,id obj2){};
Block其实可以看作JS里面的(){}();方法以及.Net中的匿名方法,即不需要声明就直接使用的方法,主要用处包括回调、事件处理和排序。声明和实现可以分开,也可以写在一起:
[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");
对于NSArray排序或者其他需要Block作为参数的函数来说,可以写成下面两种形式:
//声明和使用
[plain]
NSComparison ( ^ageComparator )( id, id ) = ^( id o1, id o2 ) {
// 比较函数的实现
};
NSArray* objs_sortedByComparator = [objs sortedArrayUsingComparator:ageComparator];
// 不声明,彻底匿名使用
NSArray* objs_sortedByComparator = [objs sortedArrayUsingComparator:^( id o1, id o2 ) { //...
}];NSComparison ( ^ageComparator )( id, id ) = ^( id o1, id o2 ) {
// 比较函数的实现
};
NSArray* objs_sortedByComparator = [objs sortedArrayUsingComparator:ageComparator];
// 不声明,彻底匿名使用
NSArray* objs_sortedByComparator = [objs sortedArrayUsingComparator:^( id o1, id o2 ) { //...
}];例子:
[plain]
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 是排好序的时间对象数组
// 按时间排序
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;
} // 时间从近到远(远近相对当前时间而言)
}];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 是排好序的时间对象数组
// 按时间排序
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;
} // 时间从近到远(远近相对当前时间而言)
}];//随机排序
[plain]
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);
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