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Legal StudiesJava 中的 set(int, obj o) 方法有什麼作用？
ArrayList 類的 set() 方法使用指定的元素替換該列表中指定位置處的元素。
示例
import java.util.ArrayList;
public class Sample {
public static void main(String args[]) {
ArrayList al = new ArrayList();
System.out.println("Initial size of al: " + al.size());
al.add("C");
al.add("A");
al.add("E");
al.add(1, "A2");
System.out.println("Size of al after additions: " + al.size());
System.out.println("Contents of al: " + al);
System.out.println("Size of al after deletions: " + al.size());
System.out.println("Contents of al: " + al);
al.set(2, "new");
System.out.println("Contents of al after setting the element: " + al);
}
}輸出
Initial size of al: 0 Size of al after additions: 4 Contents of al: [C, A2, A, E] Size of al after deletions: 4 Contents of al: [C, A2, A, E] Contents of al after setting the element: [C, A2, new, E]
更新於： 20-Feb-2020
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