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PONullPointerException and the best way to deal with it
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  1. PONullPointerException and the best way to deal with it
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    copied!<p>Note: This is homework/assignment feel not to answer if you don't want to.</p> <p>Ok after some search and reading these:</p> <p><a href="https://stackoverflow.com/questions/425439/how-to-check-if-array-element-is-null-to-avoid-nullpointerexception-in-java">How to check if array element is null to avoid NullPointerException in Java</a> <a href="https://stackoverflow.com/questions/963936/gracefully-avoiding-nullpointerexception-in-java">Gracefully avoiding NullPointerException in Java</a> <a href="http://c2.com/cgi/wiki?NullPointerException" rel="nofollow noreferrer">http://c2.com/cgi/wiki?NullPointerException</a></p> <p>Am still not making any progress on how to deal with NullPointerException error on my code, snippet for questionable code:</p> <pre><code>int findElement(String element) { int retval = 0; for ( int i = 0; i &lt; setElements.length; i++) { if ( setElements[i].equals(element) ) { // This line 31 here return retval = i; } else { return retval = -1; } } return retval; } void add(String newValue) { int elem = findElement(newValue); if( numberOfElements &lt; maxNumberOfElements &amp;&amp; elem != -1 ) { setElements[numberOfElements] = newValue; numberOfElements++; } else { System.out.println("Element " + newValue + "already exist"); } } </code></pre> <p>It compile but adding new element to a set throws a NullPointerException error.</p> <pre><code>D:\javaprojects&gt;java SetDemo Enter string element to be added A You entered A Exception in thread "main" java.lang.NullPointerException at Set.findElement(Set.java:31) at Set.add(Set.java:44) at SetDemo.main(Set.java:145) </code></pre> <p>I added another check, though honestly don't have clue if this right to line 31. if ( setElements != null &amp;&amp; setElements[i].equals(element) ) but still no joy.</p> <p>A documentation/tips or explanation is greatly appreciated.</p> <p>learning, lupin</p>
 

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