Articles

The problem...
You need a loop that runs an unknown number of times. And inside each iteration — you need to process a sequence completely.
One loop can't do both. while h…

The problem...
You've built the Caesar Cipher before. It shifted the alphabet and showed every letter's encrypted version.
But it didn't encrypt a real word. It just displayed t…

The problem...
You've built the Password Strength Checker before. It checked one password and gave a verdict.
But a real password checker doesn't stop after one try. It keeps as…

The problem...
One player knows the word. The other doesn't.
Letter by letter — the word gets revealed. Or the player runs out of chances.
The idea!
Player 1 enters the …

The problem...
Your nested loop runs too many times. Or too few. Or it modifies the wrong variable. Or it breaks out of the wrong loop.
These are the mistakes almost every begin…

The idea!
You've covered nested loops — for + for, for + if, while + for — and built real programs with all of them.
This is your reference. Everything in one place.…