NullPointerException

i am novice in oop & java, i have a problem with this error :
"Exception in thread "main" java.lang.NullPointerException"
when i want to try create new object, these lines of my code cause it
public void AddManager (Manager m){
managers[managerIndex++] = m;(in my manager class &)

n= new Manager(manName,salary,numberProject);
boss.AddManager(n); (in my main class)

plz help me:)

Hello mensa,

Welcome to the Java Forums.

Somewhere in your code a null value is being returned. Can you post the code from all your classes here and please put the [code] [/ code] tags around it. (Minus the space after /)

Thank you.

Provide some code to see pal. As Don says your code return a null value, looking at few code lines you have provide can't say much.

It should tell you where your calling the object that is null. Thankfully your working in Java because in c++ it would just find a spot in ram and call that your data, and whatever arbitrary data was there before your program now thinks that represents your object.

hello DonCash,
i wated to attach my code but i could't , then i inserted my code in my message but it failed again and this error occured:
"The site could be temporarily unavailable or too busy. Try again in a few
moments.

If you are unable to load any pages, check your computer's network
connection.

If your computer or network is protected by a firewall or proxy, make sure
that Firefox is permitted to access the Web. "

i have no firewall & proxy , is any way to solve it?
THK

- managers array could be null
- Manager(manName,salary,numberProject) constructor can do something that with the parameters and a parameter could be null
- boss instance could be null
- n could be null and boss.AddManager(n); can try to do something with n

Unless you post your full code we cannot point to the exact error.