java.lang.NullPointerException when using arrays?

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java.lang.NullPointerException when using arrays?

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Question:

Why do I keep getting a "java.lang.NullPointerException" when using arrays?

Answer:

Two possible explanations:

You've indexed past the array bounds
You haven't initialized the array correctly

   // example of an incorrectly initialized array:

       public class Test {
          public static void main(String args[]) {
             String sa[] = new String[5];
             sa[0].charAt(0);
          }
       }

    // example of a correctly initialized array:

       public class Test {
          public static void main(String args[]) {
             String sa[] = new String[5];

             for(int i = 0; i < 5; i++) {
                sa[i] = new String();
             }
 
             sa[0].charAt(0);
          }
       }