java - 如何访问子类的变量？

Question

public class Girl extends Student{...} //has firstname, lastname, id
public class Student {...}
public class School{
      Student[] arr = new girl(firstname, lastname, id)
      for(int i = 0; i<arr.length; i++){
            arr.getID(); //does this work if I have a getter in Girl class?
}
}

如果我有一个包含女孩对象的学生数组，是否可以从学校类(class)访问女孩的 ID？

Answer 1

你可以检查一下

if (arr[i] instanceof Girl)
{
    Girl girl = (Girl)arr[i];
    ...