Thread: Can't Figure out Why I am Getting Null Pointer Exception

Hello,
Following is my Code.

 
public class ClearTech {
 
 
	String EmpCode = new String();
	String EmpName;
	String Address;
	String DOB;
 
	double MonthlySalary;
	double MontlyTax;
	double NetSalary;
 
	byte NoOfDaysinMonth;
	byte NoOfLeaves;
	double NetPayableSalary;
 
	ClearTech()
	{
		EmpCode="Init Value";
		EmpName = "Init Value";
		Address = "Init Value";
		DOB = "Init Value";
	}
 
	public static void main(String[] args) {
 
		ClearTech CT = new ClearTech();
		PerEmployee PE = CT.new PerEmployee();
 
		PE.Accept();
		PE.Display();
 
	}
 
class PerEmployee
{
	int[] AnnualSalary = new int[3];
	ClearTech[] CT = new ClearTech[3];
 
	public void Accept()
	{
 
	CT[0].EmpCode = "E0001";
	CT[0].EmpName = "Bob";
	CT[0].Address = "E-12 Lajpat Nagar";
	CT[0].DOB = "01/Feb/1974";
	AnnualSalary[0] = 800000;
 
	CT[1].EmpCode = "E0002";
	CT[1].EmpName = "Kevin";
	CT[1].Address = "E-15 Mandir Marg";
	CT[1].DOB = "01/Apr/1990";
	AnnualSalary[1] = 1000000;
 
	CT[2].EmpCode = "E0003";
	CT[2].EmpName = "Mohan";
	CT[2].Address = "E-15 Mandir Marg";
	CT[2].DOB = "31/July/1984";
	AnnualSalary[2] = 400000;
 
	System.out.println("Done with Accept");
 
	}
 
	public void Display()
	{
		System.out.println("Emp Code\tName\tAddress\t\tDate of Birth\tAnnual Basic Salary");
 
		for(int i=1;i<4;i++)
		{
			System.out.println(CT[i].EmpCode+"\t"+CT[i].EmpName+"\t"+CT[i].Address+"\t"+CT[i].DOB+"\t"+AnnualSalary[i]);
		}
	}
 
}
 
class TempEmployee
{
	int RatePerWorkingDay;
}
 
}

I am not able to figure out Why I am getting a Null pointer exception. I am new to this so please help as soon as possible as the deadline for my submission is 00:00 hours today (11th March 2012). Thanks in advance.

Originally Posted by seizitp

I am not able to figure out Why I am getting a Null pointer exception.

Post the full stack trace of your NullPointerException and mark the place in your code where it's thrown with something like

 myExistingCode(anObjectIMade); // <-- NPE thrown here

Hello seizitp!
I think that your array (CT) needs to be initialised instead of just being declared(ClearTech[] CT = new ClearTech[3];) before you can assign it values. You can accomplish that by adding a for loop which initialises CT in your Accept() method. And something more; you should check again the indexes here

for(int i=1;i<4;i++)
		{
			System.out.println(CT[i].EmpCode+"\t"+CT[i].EmpName+"\t"+CT[i].Address+"\t"+CT[i].DOB+"\t"+AnnualSalary[i]);
		}

otherwise you 'll face another exeption.

Originally Posted by andreas90

Hello seizitp!
I think that your array (CT) needs to be initialised instead of just being declared(ClearTech[] CT = new ClearTech[3];) before you can assign it values. You can accomplish that by adding a for loop which initialises CT in your Accept() method. And something more; you should check again the indexes here

for(int i=1;i<4;i++)
		{
			System.out.println(CT[i].EmpCode+"\t"+CT[i].EmpName+"\t"+CT[i].Address+"\t"+CT[i].DOB+"\t"+AnnualSalary[i]);
		}

otherwise you 'll face another exeption.

Hello Andreas90,

Thanks for the correction in the java code. I got it corrected. But my problem still persists. I declared a Constructor for the Parent class (ClearTech) in this case. But still getting the same error. Array of objects is really confusing me. I would really appreciate if you show me an example as of how to Initialize the Array of objects before they could be used.

Thanks in advance.

There are plenty of initialising arrays examples in the Internet. Google is always your best friend.

          public void initialiseArray {
             Empoloyee[] employee = new Employee[5];
             for(int i = 0; i < employee.length; i++) {
                employee[i] = new Employee();
             }
          }