图片来源于我的穆斯林好友

看到书中的小题，牛刀小试。

package student;
class Student{
    private String name ;
    private int age ;
    public Student(){}
    public Student(String name){
        this.name=name;
    }
    public Student(String name,int age){
        this(name);
        this.age=age;
    }
    public void setName(String name){
        this.name=name;
    }
    public void setAge(int age){
        this.age=age;
    }
    public String getName(){
        return name;
    }
    public int getAge(){
        return age;
    }
    public void eat(){
        System.out.println("不想吃");
    }
    public void say(Student s){
        System.out.println(""+s.name+",ni给我去拿吃的");
        s.bring();
    }
    public void bring(){
        System.out.println(""+this.name+"拿来了");
    }
    public void bring(Student s){
        System.out.println(s.name+"给"+this.name+"拿来了水果");
    }
}
public class Hello01{
    public static void main(String[] args){
        Student[] stu=new Student[5];
        Student zhang=new Student("zhangzhang ");
        Student li=new Student("lili");
        Student wang=new Student("wang");
        Student jin=new Student("jinjin",15);
        Student xie=new Student("xieie",23);
        stu[0]=zhang;
        stu[1]=li;
        stu[2]=wang;
        stu[3]=jin;
        stu[4]=xie;
        new Hello01().search("xieie",stu);
        stu[1].eat();
        stu[2].say(stu[3]);
        stu[4].bring();
        stu[2].bring(stu[3]);

    }
    public  void search(Student s,Student[] stu){
        if(s!=null){
            System.out.println(" "+s.getName()+" "+s.getAge());
        }
    }
    public  void search(String name,Student[] stu){
        for(Student s:stu){
            if(name.equalsIgnoreCase(s.getName())){
                System.out.print(" "+s.getName()+" "+s.getAge());
            }
        }
    }
    public  void search(int age,Student[] stu){
        for(Student s:stu){
            if(age==s.getAge()){
                System.out.print(" "+s.getName()+" "+s.getAge());
            }
        }
    }

}

Student[] stu=new Student[5];
定义一个Student类型的数组，并动态初始化，所有的初始话值为null
在开始的时候，写了** stu[0].setName("zhangzhang");
出现错误：引用空值**

**** 清醒小刻 ****
*** 没错，我说的都是错的 ***