Common questions
The questions beginners ask most, one per lesson, each with a plain answer and the usual mix-ups explained. 61 questions so far; you have reviewed 0.
Python22 questions
- Is a program that only prints one line a real program?From the lesson “Hello, World!”
- Does a Python variable have a type?From the lesson “Variables & Data Types”
- Is indentation in Python just a style choice?From the lesson “Control Flow”
- Is a function worth writing if I only call it once?From the lesson “Functions”
- Can I just use a list for everything?From the lesson “Lists, Dicts & Sets”
- Does importing a module run its code?From the lesson “Modules & Packages”
- Should I check for problems first, or just try it and handle the error?From the lesson “Error Handling”
- Should a beginner build a whole program before mastering the parts?From the lesson “Mini Project: CLI Todo App”
- Should I use classes for every kind of data?From the lesson “Classes & OOP”
- Does it matter if I close a file after reading it?From the lesson “File I/O”
- Is a comprehension just a shorter loop?From the lesson “Comprehensions & Generators”
- Does a decorator change the function it decorates?From the lesson “Decorators & Functional Tools”
- Do type hints make Python a statically typed language?From the lesson “Type Hints & Modern Python”
- Is a generator a kind of list?From the lesson “Iterators & Generators”
- Does asyncio make my program run in parallel?From the lesson “Async & Concurrency”
- Do tests slow me down?From the lesson “Testing, Virtual Environments & Packaging”
- Can a Python string be changed?From the lesson “Strings, Deeply”
- Should I use regular expressions for all text matching?From the lesson “Regular Expressions”
- Is JSON the same as a Python dictionary?From the lesson “Working with JSON”
- Do I need the special containers when dict and list already exist?From the lesson “collections & itertools”
- Is recursion just a trick for showing off?From the lesson “Recursion”
- Does an error message mean I failed?From the lesson “Debugging & Reading Tracebacks”
JavaScript6 questions
- Are var, let and const just three names for the same thing?From the lesson “Variables & Types”
- Is an arrow function just a shorter way to write function?From the lesson “Functions & Arrow Functions”
- Does await pause the whole program?From the lesson “Promises & Async/Await”
- Does a variable disappear when its function returns?From the lesson “Closures & Scope”
- Does catching every error make a program robust?From the lesson “Error Handling & Debugging”
- Does "this" refer to the function it's written in?From the lesson “"this", Prototypes & the Object Model”
TypeScript2 questions
React2 questions
Vue1 question
Node.js1 question
HTML1 question
CSS2 questions
SQL4 questions
- Are the rows in a table stored in order?From the lesson “Tables & SELECT”
- Can a column be in SELECT without being in GROUP BY?From the lesson “COUNT, SUM & GROUP BY”
- Should I split data across tables at all?From the lesson “JOINs — Combining Tables”
- Can I trust a single statement to keep the database consistent?From the lesson “Transactions & Safety”