主题:java.lang.NullPointerException 急急急急急急急用!!
java.lang.NullPointerException问题.急用!
public class Dog {
Dog(String name,double age){
setName(name);
setAge(age);
}
Dog(String name,int age){
setName(name);
setAge(age);
}
public void setName(String name){
Name=name;
}
public void setAge(double age){
Age=age;
}
public void setAge(int age){
Age=age/7.0;
}
public String getName(){
return Name;
}
public double getAge(){
return Age;
}
public String toString(){
String dogId=this.getName()+"\t"+Double.toString(this.getAge());
return dogId;
}
public void update(String name,double age){
setName(name);
setAge(age);
}
private String Name;
private double Age;
}
以上是Dog类下面是驱动类
1.import java.util.*;
2.public class Kennel {
3. public static void main(String[] args) {
4.
5. final int SIZE_OF_DOGS=6;
6. Dog[] allDogs=null;
7. System.out.println("The initial information of " +"the dogs is as follows:\nName\tAge\n\n");
8. for(int i=0;i<SIZE_OF_DOGS;i++){
9. String name="dog"+Integer.toString(i+1);
10. double age=1.50+i;
11. allDogs[i]=new Dog(name,age);
12. System.out.println(allDogs[i].toString());
13. }
//更新Name,Age
System.out.println("After update:\nName\tAge");
String[] nameToUpdate=null;
String [] ageToUpdate=null;
Scanner scan1=new Scanner(System.in);
Scanner scan2=new Scanner(System.in);
for(int i=0;i<SIZE_OF_DOGS;i++){
nameToUpdate[i]=scan1.next();
ageToUpdate[i]=scan2.next();
allDogs[i].update(nameToUpdate[i], Double.parseDouble(ageToUpdate[i]));
}
}
}
运行后提醒Exception in thread "main" java.lang.NullPointerException
at Kennel.main(Kennel.java:11)
在第十一行出现问题,该怎么解决?
public class Dog {
Dog(String name,double age){
setName(name);
setAge(age);
}
Dog(String name,int age){
setName(name);
setAge(age);
}
public void setName(String name){
Name=name;
}
public void setAge(double age){
Age=age;
}
public void setAge(int age){
Age=age/7.0;
}
public String getName(){
return Name;
}
public double getAge(){
return Age;
}
public String toString(){
String dogId=this.getName()+"\t"+Double.toString(this.getAge());
return dogId;
}
public void update(String name,double age){
setName(name);
setAge(age);
}
private String Name;
private double Age;
}
以上是Dog类下面是驱动类
1.import java.util.*;
2.public class Kennel {
3. public static void main(String[] args) {
4.
5. final int SIZE_OF_DOGS=6;
6. Dog[] allDogs=null;
7. System.out.println("The initial information of " +"the dogs is as follows:\nName\tAge\n\n");
8. for(int i=0;i<SIZE_OF_DOGS;i++){
9. String name="dog"+Integer.toString(i+1);
10. double age=1.50+i;
11. allDogs[i]=new Dog(name,age);
12. System.out.println(allDogs[i].toString());
13. }
//更新Name,Age
System.out.println("After update:\nName\tAge");
String[] nameToUpdate=null;
String [] ageToUpdate=null;
Scanner scan1=new Scanner(System.in);
Scanner scan2=new Scanner(System.in);
for(int i=0;i<SIZE_OF_DOGS;i++){
nameToUpdate[i]=scan1.next();
ageToUpdate[i]=scan2.next();
allDogs[i].update(nameToUpdate[i], Double.parseDouble(ageToUpdate[i]));
}
}
}
运行后提醒Exception in thread "main" java.lang.NullPointerException
at Kennel.main(Kennel.java:11)
在第十一行出现问题,该怎么解决?