NSMutableDictionary

//获取字典的数量

NSInteger count=[dict2 count];

NSLog(@”%ld”,count);

3:根据key获取相应的value对象

//根据key获取相应的value对象

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NSString *value=[dict2 objectForKey:@”key1”];

NSLog(@”%@”,value);

4:把字典的key转换成枚举对象用于遍历

NSEnumerator *enumerator=[dict2 keyEnumerator];

5:获取所有的key集合

//获取所有的key集合

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NSArray *keys= [dict2 allKeys];

NSLog(@”%@”,keys);

6：获取所有的value集合

//获取所有的value集合

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NSArray *values=[dict2 allValues];

NSLog(@”%@”,values);

三:可变字典NSMutableDictionary继承自NSDictionary

1:初始化字典

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//初始化字典

NSMutableDictionary *mutableDic=[[NSMutableDictionary alloc]initWithObjectsAndKeys:@”v1”,@”k1”,@”v2”,@”k2”,@”v3”,@”k3”,@”v4”,@”k4”,@”v5”,@”k5”, nil];

2:向字典中添加指定的字典

//向一个字典中添加一个字典

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NSDictionary *dict4=[NSDictionary dictionaryWithObject:@”v6” forKey:@”k6”];

[mutableDic addEntriesFromDictionary:dict4];

NSLog(@”%@”,mutableDic);

3:向字典中添加value和key

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//向字典中添加value和key

[mutableDic setValue:@”object” forKey:@”key”];

4：创建空的字典,然后设置新的一个字典

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//创建空的字典,然后设置新的一个字典,把会之前的字典全部覆盖掉

NSMutableDictionary *mutableDict2=[NSMutableDictionary dictionary];

[mutableDict2 setDictionary:mutableDic];

NSLog(@”%@”,mutableDict2);

5:删除指定key的value值

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//移除指定key的value值

[mutableDict2 removeObjectForKey:@”k4”];

NSLog(@”%@”,mutableDict2);

6：删除移除key集合的value值

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//删除一组key的value值

NSArray *arrayKeys=[NSArray arrayWithObjects:@”k1”,@”k2”,@”k3”, nil];

[mutableDict2 removeObjectsForKeys:arrayKeys];

NSLog(@”%@”,mutableDict2);

7:删除字典中所有的value

//删除字典中所有的数据

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[mutableDict2 removeAllObjects];

NSLog(@”%@”,mutableDict2);

四:枚举遍历

1:一般遍历

//一般遍历

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NSArray *allKeys=[mutableDic allKeys];

for (NSInteger i=0; i<[allKeys count]; i++) {

NSString *obj=[mutableDic objectForKey:[allKeys objectAtIndex:i]];

NSLog(@"%@",obj);

}

2：快速枚举

//快速遍历

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for (id key in mutableDic) {

NSString *object=[mutableDic objectForKey:key];

NSLog(@”%@”,object);

}

3：迭代器枚举

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//枚举器

NSEnumerator *enumerator1= [mutableDic keyEnumerator];

id key=[enumerator1 nextObject];

while (key) {

id object=[mutableDic objectForKey:key];

NSLog(@”%@”,object);

key=[enumerator1 nextObject];

}