Debug and fix an application crash (uncaught exception) (Associate Android Developer Certification)

Let’s create uncaught exception

String word = null;
char[] letters = word.toCharArray();

We get such a log:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'char[] java.lang.String.toCharArray()' on a null object reference
at com.gayratrakhimov.logsandbox.MainActivity.onCreate(

We can see that this exception caused because something is null. In our case, String name is null. Here is highlighted and underlided. Click on it, and you can see where exception was happened.

char[] letters = word.toCharArray();

Let’s fix this code:

String word = "Joe";
char[] letters = word.toCharArray();

Very easy!