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];

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);