java中所有的类都是Object的子类,Object中实现了toString方法,在调用输出函数System.out.println(ob)时,默认调用对象ob所属类的toString方法。现对toString方法进行重载。
public class JavaTest { public static void main(String[] args) { Student stu=new Student("cjc",24); Worker wor=new Worker("cjc",24); System.out.println(stu); System.out.println(wor); } } class Student { private String name; private int age; Student(String str,int num) { name=str; age=num; } public String toString() { return "My name is "+name+",I'm "+age+"."; } } class Worker { public String name; public int age; Worker(String str,int num) { name=str; age=num; } }