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;
	}
}

java中的toString函数