学生数据增删改查--链表

先建立学生模型：

 再建立链表业务模型：

public class MyLink
{
    public Student s;
    public MyLink nextone;

    public MyLink()
    {
    }

    public MyLink(Student x)
    {
        s = x;
        nextone = null;
    }

    // add
    public void add(Student x)
    {
        MyLink pre=this,t = nextone;
        while (t != null)
        {
            pre=t;
            t = t.nextone;
        }
        pre.nextone = new MyLink(x);
        System.out.println("add success.");
    }

    // delete
    public void del(Student x)
    {
        MyLink pre = this, p = nextone;
        Student t;
        while (p != null)
        {
            t = p.s;
            if (t.name.equals(x.name) && t.age == x.age)
            {
                pre.nextone = p.nextone;
                // p=p.nextone;连续删除应该有这句，无下句
                break;
            }
            else
            {
                pre = p;
                p = pre.nextone;
            }
        }
    }

    // modify--modi age by name
    public void modi(String x, int y)
    {
        MyLink t = nextone;
        while (t != null)
        {
            if (t.s.name.equals(x))
            {
                t.s.age = y;
                break;// 连续修改应该没有这句
            }
            t = t.nextone;
        }
    }

    // get student by xm
    public Student get(String x)
    {
        MyLink t = nextone;
        while (t != null)
        {
            if (t.s.name.equals(x))
            {
                return t.s;
            }
            t = t.nextone;
        }
        return null;
    }
    //display all
    public void displayAll()
    {
        MyLink t = nextone;
        while (t != null)
        {
            t.s.showMe();
            t = t.nextone;
        }
    }
}

主程序调用：

 运行结果：

先理解，然后写一下。

会写了，就用链表改写书上的例子。