Object类中toString方法

/*public class ToStringMethod{String str;int age;public static void main(String args[]){ToStringMethod train=new ToStringMethod();System.out.println(train);}}*/public class ToStringMethod{String str;int age;public String toString(){return ("My name is "+this.str);}public static void main(String args[]){ToStringMethod train=new ToStringMethod();System.out.println(train);}}

直接打印引用时。会调用其toString()方法，这一点必须注意！