I'm just stuck on error "Exception in thread "main" java.lang.NullPointerException" Please tell me the mistake I'm committing, with solution. its a simple array. How i can access the method setAge(int) from this array.
Person arr[] = new Person[2];
arr[0].setAge(20);
Thanks.
You are creating an array with two empty slots. Populate these slots first:
arr[0] = new Person();
arr[1] = new Person();
Or for a big array use a loop:
for(int personIndex = 0; personIndex < arr.size; personIndex++)
{
arr[personIndex] = new Person();
}
You never initialize any of the objects in your array.
arr[0] = new Person();
You have not initialized array of persons. First initialize object of array like this
Person arr[] = new Person [2];
arr[0]=new Person ();
arr[1]=new Person ();
Now set age of person :-
arr[0].setAge(20);
arr[1].setAge(25);
new Person[2] creates an array which can hold two person objects at arr[0] and arr[1] (basically equal to null).But you have not initialized arr[0] to a new Person object at each location. So when try to set value for the object locating at arr[0] you are trying to set the age to a null object which throws you a null pointer exception..
