java.lang.NullPointerException错误
这是显示错误的程序示例运行的一部分java.lang.NullPointerException错误,java,Java,这是显示错误的程序示例运行的一部分 Please enter your the number of your selection : 5 Enter the blood Type : b Exception in thread "main" java.lang.NullPointerException at Hospital.getNumberOfPatientsBlood(Hospital.java:136) at Hospital.main(Hospital.java:71) 我有这个错误
Please enter your the number of your selection : 5
Enter the blood Type : b
Exception in thread "main" java.lang.NullPointerException
at Hospital.getNumberOfPatientsBlood(Hospital.java:136)
at Hospital.main(Hospital.java:71)
我有这个错误,我不知道怎么了。它应该给我一个信息,说有一个零病人的血型是B
这是显示错误的部分:
方法:
public static int getNumberOfPatientsBlood( String bloodT ){
int bloodTypeCount=0;
for (int j =0; j<hospitalPatient.length;j++){
if (hospitalPatient[j].equals(bloodT))
bloodTypeCount++;
else
continue;
}
return -1 ;
}
我猜hospitalPatient为空,请先初始化它。如何填充
hospitalPatient
数组?是否初始化了hospitalPatient数据结构?
case 5:
input.nextLine();
System.out.print("Enter the blood Type : ");
String searchBloodType = input.nextLine();
if (getNumberOfPatientsBlood(searchBloodType)!=-1)
System.out.println("the total number of patients having the same Blood Type: "+getNumberOfPatientsBlood(searchBloodType));
break;