Java中的HashMap轉換為TreeMap的程式
首先建立一個 HashMap -
Map<String, String> map = new HashMap<>(); map.put("1", "One"); map.put("2", "Two"); map.put("3", "Three"); map.put("4", "Four"); map.put("5", "Five"); map.put("6", "Six");
現在,將上述 HashMap 轉換為 TreeMap -
Map<String, String> treeMap = new TreeMap<>(); treeMap.putAll(map);
示例
以下是 Java 中將 HashMap 轉換為 TreeMap 的程式 -
import java.util.*; import java.util.stream.*; public class Demo { public static void main(String args[]) { Map<String, String> map = new HashMap<>(); map.put("1", "One"); map.put("2", "Two"); map.put("3", "Three"); map.put("4", "Four"); map.put("5", "Five"); map.put("6", "Six"); map.put("7", "Seven"); map.put("8", "Eight"); map.put("9", "Nine"); System.out.println("HashMap = " + map); Map<String, String> treeMap = new TreeMap<>(); treeMap.putAll(map); System.out.println("TreeMap (HashMap to TreeMap) " + treeMap); } }
輸出
HashMap = {1=One, 2=Two, 3=Three, 4=Four, 5=Five, 6=Six, 7=Seven, 8=Eight, 9=Nine} TreeMap (HashMap to TreeMap) {1=One, 2=Two, 3=Three, 4=Four, 5=Five, 6=Six, 7=Seven, 8=Eight, 9=Nine}
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