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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.

Este exercício faz parte do curso

Introduction to Testing in Java

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Instruções do exercício

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

Exercício interativo prático

Experimente este exercício completando este código de exemplo.

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.");
    }
}
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