数组、字典（16.5.11）

/数组排序

    //@"41", @"23", @"3", @"45", @"6", @"100", nil

    //@"hello", @"world", @"thanks", @"good", @"boy", @"list", nil

    //利用可变数组排序

    NSMutableArray *mutableAry = [NSMutableArray arrayWithObjects:@"41", @"23", @"3", @"45", @"6", @"100", nil];

    //排序方式1(调用NSMutableArray的sortUsingFunction:方法和自定义的比较方法)

    [mutableAry sortUsingFunction:compare context:nil];//从小到大排序

    for (NSString *num in mutableAry)

    {

        NSLog(@"%@", num);

    }

    return;

    //排序方式2(调用NSMutableArray的sortUsingComparator:方法和自定义的block语句块)

    [mutableAry sortUsingComparator:^NSComparisonResult(id obj1, id obj2) {

        //从小到大排序

        if ([obj1 integerValue] > [obj2 integerValue])

        {

            return 1;

        }

        else if ([obj1 integerValue] < [obj2 integerValue])

        {

            return -1;

        }

        return 0;

        //NSString *str1 = (NSString*)obj1;

        //NSString *str2 = (NSString*)obj2;

        //return [str1 compare:str2];

    }];

    for (NSString *num in mutableAry)

    {

        NSLog(@"%@", num);

    }

    return;

//利用不可变数组排序

    NSArray *tmpAry = [NSArray arrayWithObjects:@"41", @"23", @"3", @"45", @"6", @"100", nil];

    //排序方式3(调用NSArray的sortedArrayUsingFunction:方法和自定义的比较方法)

    tmpAry = [tmpAry sortedArrayUsingFunction:compare context:nil];

    for (NSString *num in tmpAry)

    {

        NSLog(@"%@", num);

    }

    return;

    //排序方式4(调用NSArray的sortedArrayUsingComparator:和自定义的block语句块)

    tmpAry = [tmpAry sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {

        //从小到大排序

        if ([obj1 integerValue] > [obj2 integerValue])

        {

            return 1;

        }

        else if ([obj1 integerValue] < [obj2 integerValue])

        {

            return -1;

        }

        return 0;

        //NSString *str1 = (NSString*)obj1;

        //NSString *str2 = (NSString*)obj2;

        //return [str1 compare:str2];

    }];

    for (NSString *num in tmpAry)

    {

        NSLog(@"%@", num);

    }

字典基本概念和常用方法：

Foundation中的字典(NSDictionary,NSMutableDictionary)是由键－值对组成的数据集合。

通过key(键)，查找对应的value（值），key通常是字符串对象，也可以是其他类型对象。

在一个字典对象中，key的值必须是唯一的。此外，字典对象的键和值不可以为空（nil）。

//字典的初始化

    //(1)调用系统创建方法(系统创建的方法已经加了autorelease)，不需要release

    //创建一个空字典

    NSDictionary *dic = [NSDictionary dictionary];

    NSLog(@"%@", dic);

    // 用一个元素初始化

    NSNumber *numObj = [NSNumber numberWithInt:100];

    NSDictionary *dic2 = [NSDictionary dictionaryWithObject:numObj forKey:@"key"];

    //或者

    NSDictionary *dic2_1 = @{@"key":numObj};

    NSLog(@"%@ %@", dic2, dic2_1);

    // 用多个元素初始化

    NSNumber *numObj2 = [NSNumber numberWithInt:100];

    NSDictionary *dic3 =[NSDictionary dictionaryWithObjectsAndKeys:numObj,@"key1",numObj2,@"key2", nil];

    //或者

    NSDictionary *dic3_1 = @{@"key1":numObj, @"key2":numObj2};

    NSLog(@"%@ %@", dic3, dic3_1);

    // 用一个字典初始化

    NSDictionary *otherDic = [NSDictionary dictionaryWithObject:@"hello" forKey:@"H"];

    NSDictionary *dic4 = [NSDictionary dictionaryWithDictionary:otherDic];

    NSLog(@"%@", dic4);

    //用文件内容初始化字典，与文件有关 后续讲解

//    NSDictionary *dic5 = [NSDictionary dictionaryWithContentsOfFile:@"test.plist"];

    //(2)自己alloc的对象并初始化，需要release或autorelease

    NSDictionary *dic6 = [[NSDictionary alloc] init];

    NSLog(@"%@", dic6);

    NSDictionary *dic7 = [[NSDictionary alloc] initWithObjectsAndKeys:

                          @"value2", @"key1", @"value2", @"key2", nil];

    NSLog(@"%@", dic7);

    NSDictionary *dic8 = [[NSDictionary alloc] initWithDictionary:otherDic];

    NSLog(@"%@", dic8);

//    NSDictionary *dic9 = [[NSDictionary alloc] initWithContentsOfFile:@"test.plist"];

NSDictionary *dic =[NSDictionary dictionaryWithObjectsAndKeys:@"hello", @"key", @"thanks",

                        @"key2", @"xcode", @"key3", @"love", @"key4", nil];

    //获取字典数量

    NSInteger count = [dic count];

    NSLog(@"总个数%d", count);

    //通过key获取对应的value对象

    NSString *valueObj = [dic objectForKey:@"key"];

    NSLog(@"%@", valueObj);

    //通过value获取对应的key数组(字典中允许有相同的value，但不允许有相同的key)

    NSArray *keyAry = [dic allKeysForObject:valueObj];

    for (NSString *key in keyAry)

    {

        NSLog(@"%@", key);

    }

    //获取所有键的集合

    NSArray *keys = [dic allKeys];

    NSLog(@"%@", keys);

    //获取所有值的集合

    NSArray *values = [dic allValues];

    NSLog(@"%@", values);

    NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:@"v1", @"key1",@"v2", @"key2",

                         @"v3", @"key3", nil];

    //快速遍历

    for (NSString *key in dic)

    {

        id obj = [dic objectForKey:key];

        NSLog(@"%@", obj);

    }

    //一般遍历

    NSArray *keys = [dic allKeys];

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

    {

        id key = [keys objectAtIndex:i];

        id obj = [dic objectForKey:key];

        NSLog(@"%@", obj);