如何複製或克隆一個 Java ArrayList?


 java.util.ArrayList 類的 clone() 方法返回此 ArrayList 例項的淺複製(即元素自身不會被複制)。使用此方法,可以將一個數組列表的內容複製到另一個數組列表中。

示例

import java.util.ArrayList;

public class ArrayListDemo {
   public static void main(String args[]) {
      ArrayList<StringBuilder> arrlist1 = new ArrayList<StringBuilder>();
      arrlist1.add(new StringBuilder("Learning-"));
      ArrayList arrlist2 = (ArrayList) arrlist1.clone();
      StringBuilder strbuilder = arrlist1.get(0);
      strbuilder.append("list1, list2-both pointing to the same StringBuilder");
      System.out.println("The 1st list prints: ");
      for (int i = 0; i < arrlist1.size(); i++) {
         System.out.print(arrlist1.get(i) + " ");
      }
      System.out.println("The 2nd list prints the same i.e:");
      for (int i = 0; i < arrlist2.size(); i++) {
         System.out.print(arrlist2.get(i));
      }
   }
}

輸出

The 1st list prints:
Learning-list1, list2 - both pointing to the same StringBuilder
The 2nd list prints the same i.e:
Learning-list1, list2 - both pointing to the same StringBuilder

更新於: 2020-02-25

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