类的构造器(alt+insert快速生成构造器)

有参和无参

package org.example;
import java.util.Arrays;

public class Main
{
    public static void main(String[] args)
    {
        stu stu1=new stu("n");
        System.out.println(stu1.name);
    }

}
class stu {
    String name;
    ///new关键字本质在调用构造器
    //无参构造
    public stu()
    {
        this.name="sb";
    }
    //有参构造，一旦有有参构造，就也得显示定义无参构造

    public stu(String name)
    {
        this.name=name;
    }
}