NSDictionary 使用总结

NSDictionary使用小结

 

#import <Foundation/Foundation.h>


int main(int argc, const char * argv[])
{

    @autoreleasepool {

        //创建字典
        NSDictionary *dic1 = [NSDictionary dictionaryWithObject:@"value" forKey:@"key"];
        NSLog(@"dic1 :%@", dic1);


        //创建多个字典
        NSDictionary *dic2 = [NSDictionary dictionaryWithObjectsAndKeys:
                              @"value1", @"key1",
                              @"value2", @"key2",
                              @"value3", @"key3",
                              @"value4", @"key4",
                              nil];
        NSLog(@"dic2 :%@", dic2);


        //根据现有的字典创建字典
        NSDictionary *dic3 = [NSDictionary dictionaryWithDictionary:dic2];
        NSLog(@"dic3 :%@", dic3);


        //根据key获取value
        NSLog(@"key3 value :%@", [dic3 objectForKey:@"key3"]);

        //获取字典数量
        NSLog(@"dic count :%d", dic3.count);

        //所有的键集合
        NSArray *keys = [dic3 allKeys];
        NSLog(@"keys :%@", keys);

        //所有值集合
        NSArray *values = [dic3 allValues];
        NSLog(@"values :%@", values);



        NSMutableDictionary *mutableDic = [[NSMutableDictionary alloc] initWithObjectsAndKeys:
                                           @"mvalue1", @"mkey1",
                                           @"mvalue2", @"mkey2", nil];
        //添加现有的字典数据
        [mutableDic addEntriesFromDictionary:dic3];
        NSLog(@"mutableDic :%@",mutableDic);

        //添加新的键值对象
        [mutableDic setValue:@"set1" forKey:@"setKey1"];
        NSLog(@"set value for key :%@",mutableDic);

        //以新的字典数据覆盖旧的字典数据
        [mutableDic setDictionary:dic2];
        NSLog(@" set dictionary :%@",mutableDic);

        //根据key删除value
        [mutableDic removeObjectForKey:@"key1"];
        NSLog(@"removeForkey :%@",mutableDic);

        //快速遍历
        for(id key in mutableDic) {
            NSLog(@"key :%@  value :%@", key, [mutableDic objectForKey:key]);
        }

        //枚举遍历
        NSEnumerator *enumerator = [mutableDic keyEnumerator];
        id key = [enumerator nextObject];
        while (key) {
            NSLog(@"enumerator :%@", [mutableDic objectForKey:key]);
            key = [enumerator nextObject];
        }


        //根据key数组删除元素
        [mutableDic removeObjectsForKeys:keys];
        NSLog(@"removeObjectsForKeys :%@",mutableDic);

        [mutableDic removeAllObjects];
        //删除所有元素
        NSLog(@"remove all :%@", mutableDic);
    }
    return 0;
}

 

日志:

 

 

NSDictionary 使用总结

 

NSArray *m_array = [NSArray arrayWithObjects:@"first",@"second",nil];
NSArray *n_array = [NSArray arrayWithObjects:@"one",@"two",@"three",nil];
//使用类方法初始化,系统自动释放内存
NSDictionary *test_dictionary = [NSDictionary dictionaryWithObjectsAndKeys:m_array,@"sort",n_array,@"number",nil];

//获取字典包含对象数目
int dict_size = [test_dictionary count];
//访问字典中的值
NSArray *sort_array = [test_dictionary objectForKey:@"sort"];
//获取键值
NSArray *keys = [test_dictionary allKeysForObject:sort_array];
//获取字典中所有值，数组
NSArray *all_value = [test_dictionary allValues];
//快速枚举
for(id key in test_dictionary)
{
    NSLog(@"key: %@,value: %@",key,[test_dictionary objectForKey:key]);
}
//如果字典只包含属性列表对象(NSData,NSDate,NSNumber,NSString,NSArray或NSDictionary)可以保存到文件中
NSString *filePath = [[[NSBundlemainBundle]resourcePath]stringByAppendingPathComponent:@"test_dict.plist"];
[test_dictionary writeToFile:filePath atomically:YES];
//用文件填充
NSDictionary *myDict =[NSDictionary dictionaryWithContentsOfFile:filePath];

//可变字典
NSMutableDictionary *dictMutable = [[NSMutableDictionary alloc]initWithObjectsAndKeys:m_array,@"sort",n_array,@"number", nil];
NSString *str = @"10_10";
//修改对象
[dictMutable setObject:string4 forKey:@"sort"];
//删除对象
[dictMutable removeObjectForKey:@"number"];
//删除多个对象
NSArray *key_array =[NSArray arrayWithObjects:@"sort",@"number", nil];
[dictMutable removeObjectForKey:key_array];
//删除所有对象
[dictMutable removeAllObjects];