http://www.programmersheaven.com/ Contains the latest posts from the thread 'ArrayLIst Problem, help me to find the errors!' posted on the 'Java' forum at Programmer's Heaven. en Copyright 2013 Programmers Heaven Sat, 18 May 2013 05:13:56 -0700 Sat, 18 May 2013 05:13:56 -0700 Argotic Syndication Framework 2007.3.0.1, http://www.codeplex.com/Argotic http://www.rssboard.org/rss-specification 360 http://www.programmersheaven.com/images/ph.gif http://www.programmersheaven.com/ 88 31 http://www.programmersheaven.com/mb/java/429121/429121/arraylist-problem-help-me-to-find-the-errors/ Hi, here is part of my code, after compilation, I get a Null Pointer Exception on the ORANGE part, I don't know where goes wrong.<br /> <br /> for (int i = 0; i &lt; N_BITS; i++){<br /> ResultButton button = new ResultButton(0);<br /> add(button, constraint);<br /> <span style="color: Orange;">resArr.add(button);</span><br /> }<br /> <br /> Note:<br /> 1. N_BITS is a just a constant.<br /> 2. resArr is an ArrayList, containing ResultButton, instance variable.<br /> 3. class ResultButton is defined by myself.<br /> <br /> HELP ME TO FIGURE OUT THE PROBLEM, THANK YOU! http://www.programmersheaven.com/mb/java/429121/429121/arraylist-problem-help-me-to-find-the-errors/ Mon, 30 Jul 2012 20:23:31 -0700 Java