重写toString方法当需要将一个对象输出到显示器时,通常要调用他的toString()方法,将对象的内容转换为字符串.java中的所有类默认都有一个toString()方法默认情况下System.out.println(对象名)或者System.out.println(对象名.toString())输出的是此对象的类名和此对象对应内存的首地址如果想自定义输出信息必须重写toString()方法注意事项1.必须被声明为public2.返回类型为String3.方法的名称必须为toString,且无参数4.方法体中不要使用输出方法System.out.println()例:packageorg.tiling.scheduling.examples;classPatient{privateStringname;privatecharsex;privateintage;privatefloatweight;privatebooleanallergies;privateintid;privatestaticintcount=0;//static，用于统计人数publicvoidprint()//输出信息要写void{System.out.println("姓名："+name);//相当于this.nameSystem.out.println("序号："+id);System.out.println("性别："+sex);System.out.println("年龄："+age);System.out.println("体重："+weight);System.out.println("是否住过院："+allergies);System.out.println("当前病人数："+count);System.out.println("====================我是分隔线========================");}publicPatient(Stringname,charsex,intage,floatweight,booleanallergies){this.name=name;this.sex=sex;this.age=age;this.weight=weight;this.allergies=allergies;count++;id=count;}publicintgetId(){returnid;}publicvoidsetName(Stringname){this.name=name;}publicStringtoString(){java.text.DecimalFormatdf=newjava.text.DecimalFormat("$0.00");//$可以不加return("姓名："+name+"\n序号："+id+"\n性别："+sex+"\n年龄："+age+"\n体重："+df.format(weight)+"\n是否住过院："+allergies+"\n人数："+count+"\n=====================我是分隔线=======================");}}publicclassPatientTester{publicstaticvoidmain(Stringargs[]){PatientPatientA=newPatient("吕振",'男',21,111.101f,true);//weight不能写成111.1//PatientA.print();//使用toString方法System.out.println(PatientA);PatientPatientB=newPatient("张沛",'男',22,101.101f,false);//PatientB.print();System.out.println(PatientB.toString(