字典

#pragma mark 不可变字典

// 创建 字典

快速创建：@{key1:value1,key2:value2};

快速访问字典元素：字典名[key]

// 静态创建

NSDictionary * dic1 = [NSDictionarydictionaryWithObjectsAndKeys:@"Value1",@"Key1",@"Value2",@"Key2", nil];

// 实例创建

NSDictionary * dic2 = [[NSDictionaryalloc]initWithObjectsAndKeys:@"Value1",@"Key1",@"Value2",@"Key2", nil];

// 来自其他字典

NSDictionary * dic3 = [NSDictionarydictionaryWithDictionary:dic1];

 

// 获取字典中元素的个数

NSInteger count = [dic1 count];

 

// 获取字典的value

NSString * dicStr = [dic1 objectForKey:@"key1"];

 

// 获取字典的键和值

NSArray * keys = [dic1 allKeys];

NSArray * value = [dic1 allValues];

NSLog(@"**********%@",keys);

 

 

#pragma mark 可变字典

// 静态创建

NSMutableDictionary * muDic0 = [NSMutableDictionarydictionaryWithObjectsAndKeys:@"Value1",@"Key1",@"Value2",@"Key2", nil];

NSMutableDictionary * muDic1 = [NSMutableDictionarydictionaryWithCapacity:0];

// 实例创建

NSMutableDictionary * muDic2 = [[NSMutableDictionaryalloc]initWithCapacity:0];

 

// 向字典添加元素

[muDic2 setValue:@"Value"forKey:@"Key"];

 

// 删除指定的元素

[muDic0 removeObjectForKey:@"key1"];

 

// 向字典muDic2添加整个字典muDic0

[muDic2 addEntriesFromDictionary:muDic0];

 

// 根据指定的数组删除字典的元素

NSArray * array = [NSArrayarrayWithObjects:@"key1", nil];

[muDic0 removeObjectForKey:array];

 

// 将字典muDic2的内容设置与字典muDic0相同

[muDic2 setDictionary:muDic0];

 

// 删除所有元素

[muDic0 removeAllObjects];

 

 

// 遍历字典

for (id key in muDic0) {

id str = [muDic0 objectForKey:key];

}

 

 

NSDictionary * dictionary = @{@"name":@"jack",@"qq":@"1234",@"age":@"11"};

NSArray *index = dictionary.allKeys;

for (int i = 0; i < dictionary.count; i ++) {

NSString * key = index[i];

NSString * str = [dictionary objectForKey:key];

 

NSLog(@"%@ ：%@",key,str);

}

// block 快速遍历

[dictionary enumerateKeysAndObjectsUsingBlock:^(id_Nonnull key, id_Nonnull obj, BOOL * _Nonnull stop) {

NSLog(@"键：%@,值：%@",key,obj);

}];