Javaexamples-collection-print

Javaの例-印刷コレクション

問題の説明

コレクションを印刷するには？

溶液

Java UtilクラスのtMap.keySet（）、tMap.values（）、およびtMap.firstKey（）メソッドを使用してコレクションを印刷する方法の例を次に示します。

import java.util.*;

public class TreeExample{
   public static void main(String[] args) {
      System.out.println("Tree Map Example!\n");
      TreeMap <Integer, String>tMap = new TreeMap<Integer, String>();
      tMap.put(1, "Sunday");
      tMap.put(2, "Monday");
      tMap.put(3, "Tuesday");
      tMap.put(4, "Wednesday");
      tMap.put(5, "Thursday");
      tMap.put(6, "Friday");
      tMap.put(7, "Saturday");
      System.out.println("Keys of tree map: " + tMap.keySet());
      System.out.println("Values of tree map: " + tMap.values());
      System.out.println("Key: 5 value: " + tMap.get(5)+ "\n");
      System.out.println(
         "First key: " + tMap.firstKey() + " Value: " + tMap.get(tMap.firstKey()) + "\n");
      System.out.println(
         "Last key: " + tMap.lastKey() + " Value: "+ tMap.get(tMap.lastKey()) + "\n");
      System.out.println("Removing first data: " + tMap.remove(tMap.firstKey()));
      System.out.println("Now the tree map Keys: " + tMap.keySet());
      System.out.println("Now the tree map contain: " + tMap.values() + "\n");
      System.out.println("Removing last data: " + tMap.remove(tMap.lastKey()));
      System.out.println("Now the tree map Keys: " + tMap.keySet());
      System.out.println("Now the tree map contain: " + tMap.values());
   }
}

結果

上記のコードサンプルは、次の結果を生成します。

C:\collection>javac TreeExample.java

C:\collection>java TreeExample
Tree Map Example!

Keys of tree map: [1, 2, 3, 4, 5, 6, 7]
Values of tree map: [Sunday, Monday, Tuesday, Wednesday,
Thursday, Friday, Saturday]
Key: 5 value: Thursday

First key: 1 Value: Sunday

Last key: 7 Value: Saturday

Removing first data: Sunday
Now the tree map Keys: [2, 3, 4, 5, 6, 7]
Now the tree map contain: [Monday, Tuesday, Wednesday,
Thursday, Friday, Saturday]

Removing last data: Saturday
Now the tree map Keys: [2, 3, 4, 5, 6]
Now the tree map contain: [Monday, Tuesday, Wednesday,
Thursday, Friday]

C:\collection>