Scala HashMap containsValue方法

Question

我正在尝试将我用Java编写的算法转换为Scala,但是我遇到了containsValue()Java中存在的方法的问题.我想做类似的事情,if (hashMap.containsValue(value))但我查看了scala文档,并且只找到了一个contains(key)方法.你如何在Scala中实现或使用hashmap.containsValue(value)我仍然是Scala的新手,但这是我迄今为止在Scala中所拥有的:

def retString(s: String)
{
  val map = new mutable.HashMap[Int, Char]
  for (c <- s.toCharArray)
  {
      //if(!map.containsValue(c)) goes here
  }

}

`我试图转换的完整算法是我用Java编写的removeDuplicates:

public static String removeDuplicates(char[] s)
{

    HashMap<Integer, Character> hashMap = new HashMap<Integer, Character>();
    int current = 0;
    int last = 0;
    for(; current < s.length; current++)
    {
         if (!(hashMap.containsValue(s[current])))
         {
              s[last++] = s[current];
              hashMap.put(current, s[current]);

         }
    }
    s[last] = '\0';
    //iterate over the keys and find the values
    String result = "";
    for (Integer key: hashMap.keySet()) {
        result += hashMap.get(key);
    }
    return result;

}

Answer 1

你可以使用exists:

map.values.exists(_ == c)