Conditions (if/else)
📚 What are conditions? Conditions let your program **make decisions** instead of always doing the same thing. You ask a yes/no question in code; if the answer is true, one block runs; if not, you can run a different block with `else` or chain extra checks with `elif`.
Appy Says…
Every app you use is full of decisions. Is the user logged in? Is the score high enough? Does the password match? If/else is how code makes choices — without it, every program would just do the exact same thing every single time.
What are Conditions?
Conditions let your program make decisions. You ask a yes/no question in code — if the answer is True, one block runs; if it's False, a different block runs. This is called branching.
- •
ifruns a block only when its condition isTrue - •
elif(else-if) tries another condition when the first wasFalse - •
elsecatches every other case — your safe default - •Indentation (the 4-space gap) tells Python what belongs inside each branch
Think of it like a Roblox game checkpoint
When you reach a checkpoint, the game checks: 'Does the player have enough points to unlock the next zone?' If yes → open the gate. If not → show the 'you need more points' screen. If they've already been here → skip the cutscene. That's if / elif / else in action.
How Conditions Work — Step by Step
- •Step 1: Python evaluates your condition — the result is
TrueorFalse - •Step 2: If
True, the indented code block runs - •Step 3: If
False, Python jumps toelif(if there is one) orelse - •Step 4: Only one branch runs — once a match is found, the rest are skipped
- •Comparison operators:
==equals,!=not equal,>greater,<less,>=at least,<=at most
Real-World Examples
- •A game:
if health <= 0: show_game_over() - •A login:
if password == stored_password: grant_access() else: deny() - •YouTube age restriction:
if age < 13: block_content() - •A thermostat:
if temperature > target: turn_on_ac() elif temperature < target: turn_on_heat() - •Spotify shuffle:
if shuffle_on: pick_random_track() else: play_next_track()
Key Facts
- •Combine conditions with
and(both must be True) oror(at least one must be True) - •
notflips a boolean:not TrueisFalse - •You can nest if statements inside other if statements (called nested conditions)
- •The
:colon at the end ofif,elif,elseis required — don't forget it - •You can have many
elifbranches but only oneifand oneelse
Watch Out: = vs ==
= assigns a value (sets a variable). == compares two values. Writing if score = 10: is a common mistake — it should be if score == 10:. Python will give you a SyntaxError to catch this.
Remember
Think of conditions as questions your code asks: 'Is this true right now?' Answer yes → do this. Answer no → do that. Break every complex decision into a chain of simple yes/no questions and you'll always be able to code it.
What You Learned
- •
if condition:— runs the block when condition is True - •
elif condition:— checks another condition if the first was False - •
else:— runs when no previous condition was True - •Comparison operators:
== != > < >= <= - •Combine with
and/or/not - •Indentation defines what belongs inside each branch
Key Facts
- →Combine conditions with
and(both must be True) oror(at least one must be True) - →
notflips a boolean:not TrueisFalse - →You can nest if statements inside other if statements (called nested conditions)
- →The
:colon at the end ofif,elif,elseis required — don't forget it - →You can have many
elifbranches but only oneifand oneelse
Real-World Examples
Remember
Think of conditions as questions your code asks: 'Is this true right now?' Answer yes → do this. Answer no → do that. Break every complex decision into a chain of simple yes/no questions and you'll always be able to code it.
Quick Quiz
When does the else block run?