咖啡____With藍。-小伙

Scala:迭代映射 ; C#:遍歷(Forech)

Scala:

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

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

   3: //遍歷 key

   4: for (key<-scores.keySet)print(key+" ")

   5: println()

   6:  

   7: //遍歷 value

   8: for (value<-scores.values)print(value+" ")

   9: println()

  10:  

  11: //實驗變數 k 是否為語法糖，結果不是

  12: for (v<-scores)print(v+" ")

  13: println()

  14:  

  15: //實驗變數 k 是否為語法糖，結果不是

  16: for (k<-scores)print(k+" ")

  17: println()

  18:  

  19: //這裡的k,v為語法糖，k代表key、value 代表 value

  20: //可用這句語法 將 key Value 互換

  21: var keyValueChange= for((k,v)<-scores) yield (v,k)

  22: for (v<-keyValueChange.values)print(v+" ")

Result:

C#:

   1: Dictionary<string,int>scores=new Dictionary<string,int>();

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

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

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

   5:  

   6:  foreach (var key in scores.Keys)

   7:  {

   8:      Console.Write(key + " ");

   9:  

  10:  } 

  11: Console.WriteLine();

  12:  

  13: foreach (var value in scores.Values)

  14:  {

  15:      Console.Write(value+" ");

  16:  } 

  17: Console.WriteLine();

  18:  

  19:  

  20: Dictionary<int, string> keyValueChange = new Dictionary<int, string>();

  21: foreach (var item in scores) 

  22: { 

  23:     keyValueChange.Add(item.Value, item.Key);

  24: }

  25: foreach (var value in keyValueChange.Values) 

  26: {

  27:      Console.Write(value + " ");

  28: } 

  29: Console.WriteLine();

  30:  

  31:  

  32: Console.Read();

Result:

By-藍小伙