NSDictionary与NSMutableDictionary的常用方法

关于NSDictionary－－－－－－－－－－－－－－－－－－－－－－－－

// 第一种创建的方法

//NSNumber *num1 = [NSNumber numberWithInt:100];

NSDictionary *dic1 = [NSDictionarydictionaryWithObject:num1 forKey:@"key1"];

//第二种创建的方法

NSDictionary *dic2 = [NSDictionarydictionaryWithObjectsAndKeys:@"value1",@"key1",@"value2",@"key2",nil];

//第三种创建的方法

NSDictionary *dic3 = [NSDictionarydictionaryWithDictionary:dic1];

//通过键获取对应的值

NSString *strValue1 = [dic2objectForKey:@"key2"];//获取到的值为value2

NSString *strValue2 = [dic2objectForKey:@"key3"];//获取到的值为(null)

//获取字典的数量

int count = [dic2count];//count=2

//获取所有的键的枚举对象

NSEnumerator *enum1 = [dic2keyEnumerator];

//获取字典中所有的键和值的Array对象

NSArray *allKeys = [dic2allKeys];

NSArray *allValues = [dic2allValues];

NSMutableDictionary-----------------------------------------------------------

//创建两个字典，一个可变，一个不可变

//NSDictionary *dic4 = [NSDictionary dictionaryWithObjectsAndKeys:@"v1",@"k1",@"v2",@"k2",@"v3",@"k3",nil];

NSMutableDictionary *mdic1 = [NSMutableDictionarydictionaryWithObject:@"v100"forKey:@"k100"];

//添加一个指定的字典

[mdic1addEntriesFromDictionary:dic4];

//添加一个指定的键值对

[mdic1setObject:@"v200"forKey:@"k200"];

//创建一个空的字典

NSMutableDictionary *mdic2 = [NSMutableDictionarydictionary];

//将字典的原内容清空，用新的内容覆盖

[mdic2 setDictionary:dic4];

//根据指定的键删除字典对应的值

[mdic2removeObjectForKey:@"k2"];

//删除一组数据

NSArray *array1 = [NSArrayarrayWithObjects:@"k1",@"k2",nil];

[mdic1removeObjectsForKeys:array1];

//快速遍历字典

for(id keyin [mdic1 allKeys])

{

NSLog(@"%@",[mdic1objectForKey:key]);

}

//枚举遍历

NSEnumerator *enumer1 = [mdic1keyEnumerator];

id key;

while (key = [enumer1nextObject]) {

NSLog(@"枚举遍历:%@",[mdic1objectForKey:key]);

}