How do I increase the value of a variable when an object is clicked? (Javascript Question)

Question

I've ran into another problem while creating a virtual pet game. I want to increase the value of hunger when the leaf is clicked and print the value of hunger. What did I do wrong?
HTML: <img onclick="increase()" src="https://www.vectorportal.com/img_novi/beautiful-leaf-icon.jpg" class="leaf">
Javascript:
function increase() {
hunger++=
document.getElementById("food").innerHTML=hunger;
Here's the link to the code:
https://code.sololearn.com/We4BFeQJk50E

Answer 1

1. variable falls into functional scope at line 4.
2. typo at line 24
fix :
https://code.sololearn.com/Wd49hTq255zM/?ref=app
readings :
https://www.sololearn.com/post/45261/?ref=app

Answer 2

thank you so much Gordon !!