toString（）問題
學校作業：
編寫Java應用程序，封裝一個Student類的對象。其中定義一個表示學生的類Student，包括學號、班級、性別、年齡屬性，以及獲得學號、獲得性別、獲得性別、獲得姓名、獲得年齡、修改年齡方法。另加一個public String? toString()方法把Student類對象的所有信息組成一個字符串，并有檢測這個功能的程序體現。
使用上題編寫的Student類創建5個學生對象，并在控制臺把5個學生的信息顯示出來。
我的代碼：
package homework;
public class Student {
String name;
int id;
String ClassNum;
String sex;
int age;
public Student(String name,int id,String ClassNum,String sex,int age){
this.name=name;
this.id=id;
this.ClassNum=ClassNum;
this.sex=sex;
this.age=age;
}
public String getName(){
return this.name;
}
public int getId(){
return this.id;
}
public String getClassNum(){
return this.ClassNum;
}
public String getSex(){
return this.sex;
}
public int getAge(){
return this.age;
}
public void setAge(int age){
this.age=age;
}
public String toString(){
return "My name is "+name+".My id is"+id+".My ClassNum is"+ClassNum+".My sex is"+sex+".My age is"+age+".";
}
Student a=new Student("ZhangSan",123,"class1","boy",11);
Student b=new Student("LiSi",1234,"class1","boy",11);
Student c=new Student("WangWu",12345,"class2","boy",11);
Student d=new Student("MingMing",54321,"class2","girl",12);
Student e=new Student("XingXing",4321,"class3","girl",12);
Student f=new Student("QingQing",321,"class3","girl",12);
System.out.priltln(a);
System.out.priltln(b);
System.out.priltln(c);
System.out.priltln(d);
System.out.priltln(e);
System.out.priltln(f);
}
畫下劃線是顯示錯誤的地方。
請問要如何顯示5個學生的信息？？？
2017-03-13
找到原因了，創建對象和打印對象那幾行代碼應該寫在方法里，比如main()，而不能直接寫在類中
2017-03-14
代碼都是對的 但是你看我下面測試的不行
2017-03-14
這兩個問題
2017-03-14
package homework;
public class Calculator {
int a;
int b;
double result;
public double sum(){
double sum=a+b;
return result=sum;
}
public double sub(){
double sub=a-b;
return result=sub;
}
public double mult(){
double mult=a*b;
return result=mult;
}
public void div(){
if(b==0){
System.out.println("b!=0");
}else{
double div=a/b;
System.out.println("result="+div);
}
}
public Calculator(int a,int b){
}
}
package homework;
public class CalculatorText {
public static void main(String[] args) {
// TODO Auto-generated method stub
Calculator Calculator1 =new Calculator(3,4);
System.out.println(Calculator1.sum());
System.out.println(Calculator1.sub());
System.out.println(Calculator1.mult());
? ? ? ?Calculator1.div();
Calculator Calculator2 =new Calculator(2,1);
System.out.println(Calculator2.sum());
System.out.println(Calculator2.sub());
System.out.println(Calculator2.mult());
Calculator2.div();
}
}
2017-03-13
2017-03-13
2017-03-13
方法名拼錯了，不是priltln, 是println