新學習:構造方法的重載,給成員變量賦值
錯誤代碼:
class Student {
public static void main(String[] args) {
Person p = new Person();
p.setAge(24);
p.setName("楊洋");
p.show();
System.out.println("Hello World!");
}
//靜態方法中不能引用非靜態變量
class Person//這個類不能嵌套在類Student中,否則報錯:無法從靜態上下文中引用非靜態變量 this
{
private int age;
private String name;
public Person(){ //空參構造
}
public Person(String name, int age){//有參構造
this.name = name;
this.age = age;
}
public void setAge(int age){
this.age = age;
}
public void setName(String name){
this.name = name;
}
public int getAge(){
return age;
}
public String getName(){
return name;
}
public void show(){
System.out.println("姓名" + name + "年齡" + age);
}
}
}
修改:類Person需要從類Student中拿出來