【OC】字典

最新推荐文章于 2019-09-23 10:27:00 发布

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最新推荐文章于 2019-09-23 10:27:00 发布

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分类专栏： Objective-C

本文链接：https://blog.youkuaiyun.com/zhenglu008/article/details/41021723

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本文详细介绍了Swift编程中字典的创建、使用、遍历等关键操作，包括字典的基本语法、计数、获取键值对、遍历方法等，旨在帮助开发者深入理解并熟练运用字典这一强大的数据结构。

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#import <Foundation/Foundation.h>

#pragma mark 字典相关
void dict(){
    // 创建一个字典
    NSDictionary *dict1 = [NSDictionary dictionaryWithObject:@"value" forKey:@"key"];
    NSDictionary *dict2 = [NSDictionary dictionaryWithObjectsAndKeys:
                           @"value1", @"key1",
                           @"value2", @"key2",
                           @"value3", @"key3",
                           nil];
    NSArray *values = [NSArray arrayWithObjects:@"value1", @"value2", nil];
    NSArray *keys = [NSArray arrayWithObjects:@"key1", @"key2", nil];
    NSDictionary *dict3 = [NSDictionary dictionaryWithObjects:values forKeys:keys];
    NSLog(@"%@", dict1);
    NSLog(@"%@", dict2);
    NSLog(@"%@", dict3);
   
}

#pragma mark 字典的用法
void dict2(){
    NSDictionary *dict1 = [NSDictionary dictionaryWithObjectsAndKeys:
                           @"value1", @"key1",
                           @"value2", @"key2",
                           @"value3", @"key3",
                           nil];
    // 统计字典中的键值对
    NSUInteger num = [dict1 count];
    NSLog(@"%ld", num);
   
    // 获取字典中的值
    id obj = [dict1 objectForKey:@"key2"];
    NSLog(@"%@", obj);
   
}

#pragma mark 字典的遍历
void dict3(){
    NSDictionary *dict1 = [NSDictionary dictionaryWithObjectsAndKeys:
                           @"value1", @"key1",
                           @"value2", @"key2",
                           @"value3", @"key3",
                           nil];
    // for in遍历
    for (id key in dict1) {
        id value = [dict1 objectForKey:key];
        NSLog(@"For:%@->%@", key, value);
    }
   
    // 迭代器遍历
    [dict1 enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
        NSLog(@"Block:%@->%@", key, obj);
    }];
}

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        dict3();
    }
    return 0;
}