Every programmer should be comfortable with recursion. Recursion is a type of loop created by making a function call itself. Here’s a recursive function that loops infinitely (until the computer runs out of memory) when called: void print_stars() { cout << "*"; print_stars(); } Just like for loops and while loops, recursion can be used to do something repeatedly. Some problems are easier to solve with one kind of loop than another....

Printing emoji can be tricky because C++ running in Windows doesn’t always support UTF-8. Emoji and other Unicode symbols can be printed with C++ by copying the symbol itself into your code or by using a Unicode code point. You can find emoji and other symbols at sites like unicode-table.com or with a keyboard shortcut (Windows+. on Windows, ctrl+cmd+space on Mac, and ctrl+. on some Linux distros). On Mac and Linux, working with emoji in C++ is straightforward and doesn’t require any tricks....

You don’t need another dependency to color text. With many programming languages, you can change the color and the style of your output to a terminal using ANSI codes. Here’s how: with C++: cout << "\x1b[31m This will be red! \x1b[0m This will be the default color."; with Python: print("\x1b[31m This will be red! \x1b[0m This will be the default color.") As you can see, the string did not need to change at all even with a different programming language....

SQL (Structured Query Language) is a commonly used and reliable way for programs to store and retrieve data. In many cases, it’s much better in many ways than just using files directly. There’s a lot that can be learned about SQL. Here are some resources to get you started. Learn SQL with SQLBolt and/or The SQL Murder Mystery. Choose a database technology and tools. Databases by Full Stack Python is a guide (not entirely for Python) with various resources about databases....

Here are some great resources for learning how to use Git and GitHub. There’s more here than any one person will need, so just learn what will be helpful to you in the very near future. Watch these short videos: Version control with Git and GitHub by freeCodeCamp. Check out Better Explained’s guides to version control and Git, or the Learn X in Y minutes guide to Git. Consider starting with a Git client with a graphical interface, such as GitHub Desktop, GitButler, or Sublime Merge....

Big-O Cheat Sheet Algorithm – Wikipedia Sorting algorithm – Wikipedia Why quicksort is better than other sorting algorithms in practice App Academy has a free section about data structures and algorithms. Click the menu icon in the corner to see the list. HackerEarth Programming Tutorials and Practice Problems (when you choose one of the main topics and see a list of problems, click the subtopic you want on the left and then the “tutorial” link near the top of the page) Python algorithms for job interviews by freeCodeCamp Lecture Slides for Algorithm Design by Jon Kleinberg and Éva Tardos machine learning papers – Distill The Deadlock Empire – a game for learning concurrency Nick Johnsonz’s algorithms blog posts visualizations sorting algorithms – Toptal Explorable Explanations Data Structure Visualizations by David Galles algorithm-visualizer....

Here are a bunch of free online books. I update this page with new books occasionally. computer science Software Engineering at Google by Titus Winters, Tom Manshreck, and Hyrum Wright A Data-Centric Introduction to Computing by Fisler, Krishnamurthi, Lerner, and Politz Programming Languages: Application and Interpretation by Shriram Krishnamurthi How to Design Programs by Felleisen, Findler, Flatt, Krishnamurthi The Nature of Code by Daniel Shiffman Everything curl by Daniel Stenberg et al....