NSDictionary、NSMutableDictionary的基本用法

字典初始化

NSNumber *numObj = [NSNumber numberWithInt:100];

以一个元素初始化

NSDictionary *dic = [NSDictionary dictionaryWithObject:numObj forKey:@"key"];

初始化两个元素

NSDictionary *dic = [NSDictionary dictionaryWithObjectsAndKeys:numObj, @"valueKey", numObj2, @"value2",nil];

初始化新字典，新字典包含otherDic

NSDictionary *dic = [NSDictionary dictionaryWithDictionary:otherDic];

以文件内容初始化字典

NSDictionary *dic = [NSDictionary dictionaryWithContentsOfFile:path];

NSDictionary *dic3 = [NSDictionary dictionaryWithObject:@"v3" forKey:@"key3"];

[dic2 addEntriesFromDictionary:dic3];

[dic2 setValue:@"value3" forKey:@"key3"];

NSMutableDictionary *dic1 = [NSMutableDictionary dictionary];

[dic1 setDictionary:dic2];

[dic1 removeObjectForKey@"key1"];

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

[dic2 removeObjectsForKeys:array];

[dic1 removeAllObjects];

for (id key in dic){

     id obj = [dic objectForKey:key];

     NSLog(@"%@", obj);

}

NSArray *keys = [dic allKeys];

inr length = [keys count];

for (int i = 0; i < length；i++){

     id key = [keys objectAtIndex:i];

     id obj = [dic objectForKey:key];

     NSLog(@"%@", obj);

}

NSEnumerator *enumerator = [dic keyEnumerator];

id key = [enumerator nextObject];

while (key) {

        id obj = [dic objectForKey:key];

        NSLog(@"%@", obj);

        key = [enumerator nextObject];

}