Help writing programs!

Question

I have recently taken it upon myself to learn Java, and I am having a few problems with a few programs. I am not understanding how to do certain things when writing the program. I am taking this class as an independent study, but we have a general guideline of programs that may help us prepare for the A.P. Exam. On of the programs that I am having difficulty with is a program designed to remove blanks. I have looked on the internet and found programs, but I need to write it in a certain way using arrays.
I am using BlueJ.
What I have so far is:
import java.util.ArrayList;
public class RemoveBlanks
String withblanks;
String removeblanks;
int num = 0;
ArrayList Array;
ArrayList Letter;
Letter = new ArrayList();
Array = new ArrayList();
EasyReader kboard = new EasyReader();
withblanks = "Take out these spaces";
//System.out.println("Input a sentence to remove the blanks in.");
//withblanks = kboard.readLine();
Array.add(withblanks);
for (num = 0; num < Array.size(); num++)
Letter[num] = Array.charAt(num);
if (Letter[num] == " ")
Array.add(removeblanks);
I honestly have no idea if this even makes sense. The book I am using is expecting that you already are familiar with the syntax and the language in general. I would appreciate it if someone could help guide me on how to do this the right way. Thanks in advance!

Answer 1

In the future, post code between [co[i]de] tags. Some pointers:
1) You're confusing arrays and ArrayLists, they are two very different things.
2) All variable names should begin with lower case letters.
3) It is pointless to have two { in a row.
4) In order for a program to run, it needs a main() method.
5) Always compare Strings with the equals() method, not ==.