who is undefined

2.Ghost-Writing.md

@@ -46,4 +46,11 @@ function keyTyped() {
 * When key 'm' is pressed then "Hi Maaike!" is printed on the console
 
 2. Modify sketch 2.0 so that:
-* Every time key 'x' is pressed then print the name of the following person in the array ("Hi David!", "Hi Karin!", "Hi Sigrid!", and so forth)
+* Every time key 'x' is pressed then print the name of the following person in the array ("Hi David!", "Hi Karin!", "Hi Sigrid!", and so forth)
+
+### 🤔 Who/what is "undefined"?
+
+<p align="center">
+<img src="https://git.le-club-des-sans-sujets.org/gauthiier/Revisiting-Concepts-Notations-Software-Art/media/branch/main/img/undefined.png">	
+</p>
+