咖啡____With藍。-小伙

Scala:映射；C#:字典

Scala:

   1:  

   2: var scores=scala.collection.mutable.Map[String,Int]("Alice"-> 10,"Bob"-> 3,"Cindy"-> 8)

   3: //val scores=Map("Alice"-> 10,"Bob"-> 3,"Cindy"-> 8)

   4: println(scores ("Alice"))

   5: val result=if(scores.contains("God"))scores("God") else false

   6: //result=scores.getOrElse("God",false)

   7: println(result)

   8:  

   9: //賦值 也可更新 語法一樣

  10: //scores("God")=99

  11: scores+=("God"->99)

  12: //將插入在God以後，觀看結果Mary位置，即可發現

  13: scores+=("God"->77,"Mary"->123)

  14: println(scores("God"))

  15: println(scores)

  16: //刪除

  17: //scores=scores-"God"-"Mary"

  18: scores-=("God")

  19: scores-=("God")

  20: scores-=("God","Mary")

  21: println(scores)

Result:

C#:

   1:  

   2: Dictionary<string,int>scores=new 

   3: Dictionary<string,int>();

   4: scores.Add("Alice",10);

   5: scores.Add("Bob",3);

   6: scores.Add("Cindy", 8);

   7: Console.WriteLine(scores["Alice"]);

   8: object 

   9: result;

  10: result = scores.ContainsKey("God") ? scores["God"] as object: false 

  11: as object;

  12: Console.WriteLine(result);

  13: //賦值

  14: scores.Add("God",99);

  15: scores.Add("Mary", 123);

  16: Console.WriteLine(scores["God"]);

  17: scores.ToList().ForEach(x=>

  18:     {

  19:          Console.Write("{0}->{1},", x.Key, 

  20:         x.Value.ToString());

  21:     });

  22: Console.WriteLine();

  23: //刪除

  24: scores.Remove("God");

  25: scores.Remove("Mary");

  26: scores.ToList().ForEach(x =>

  27:     { 

  28:             Console.Write("{0}->{1},", x.Key, 

  29:             x.Value.ToString());

  30:     });

  31: Console.WriteLine();

  32: Console.Read();

Result:

心得:

Scala除了提供好識別化的語法糖，還做了很多防呆的機制，有些防呆原本若不去處理，很容易程式就會崩潰，這些小防呆常常就被遺漏了，現在不用擔心那麼多，單純寫邏輯吧。

By-藍小伙