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
Instruções do exercício
- Call a method on
name
that will result in aNullPointerException
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.");
}
}