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Edge cases: NullPointerException

Of all possible edge cases, the null variable one, where an object has not been set, is the one that tends to sneak up on programmers the most. It can arise for many reasons: someone forgot to initialize a variable, an object did not form properly, someone filled in a website form incorrectly, … The list goes on and on.

In Java, when a method is called on a null variable, a NullPointerException is thrown.

In this exercise, try to trigger a NullPointerException in the given code.

Questo esercizio fa parte del corso

Introduction to Testing in Java

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Istruzioni dell'esercizio

  • Call a method on name that will result in a NullPointerException being thrown.

Esercizio pratico interattivo

Prova a risolvere questo esercizio completando il codice di esempio.

public class NullPointer {

    private static String name;

    public static void main(String[] args) {
    	// Call a method on name that will throw a NullPointerException
        System.out.println("My name has " + name.____() + " characters.");
    }
}
Modifica ed esegui il codice