java - 如何访问子类的变量？

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Student对象数组的女孩，是否可以从School类访问该女孩的ID？

最佳答案

你可以检查

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