如何复制或克隆一个 Java ArrayList?
java.util.ArrayList 类的 clone() 方法返回此 ArrayList 实例的浅拷贝(即元素自身不会被复制)。使用此方法,可以将一个数组列表的内容复制到另一个数组列表中。
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)); } } }
输出
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
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