🔄 Changing the Value of a Variable

Variables are not permanent — you can change (update) what is stored inside them at any time. When you store a new value, the old value is gone forever.

🐍 Python — Changing a variable's value

health = 100
print("Starting health:", health)

# Player takes damage
health = 75
print("After taking damage:", health)

# Player picks up a health pack
health = 100
print("After health pack:", health)

🔍 What Happened to the Old Values?

When we wrote health = 75 on line 5, the old value (100) was thrown away and replaced with 75. Then on line 9, the 75 was thrown away and replaced with 100 again.

Think of it like erasing what is written on a whiteboard and writing something new. The old text is gone.

🧮 Updating Variables Using Their Current Value

One of the most common things in programming is updating a variable based on its current value. For example, adding 10 points to a score:

🐍 Python — Updating based on current value

score = 0
print("Starting score:", score)

# Player defeats an enemy (worth 10 points)
score = score + 10
print("After enemy defeated:", score)

# Player collects a coin (worth 5 points)
score = score + 5
print("After coin collected:", score)

# Player collects another coin
score = score + 5
print("After another coin:", score)

🧠 Understanding score = score + 10

This line confuses many beginners. Read it as: "Take the current value of score, add 10 to it, and store the result back into score."

Python looks at the right side first: score + 10 → that is 0 + 10 = 10
Python stores the result (10) into the variable on the left side: score
score now contains 10 (the old value of 0 is gone)

This pattern — variable = variable + something — is used constantly in programming. You will see it in almost every game or app.