Explain code in plain English

Explain code by language

Each page starts with a real sample to explain, then notes on what it shows.

• Explain Python codeA timing decorator, a generator that reads a CSV file and a dict comprehension.
• Explain JavaScript codeLoading several users at once with fetch and Promise.allSettled.
• Explain TypeScript codeA generic Result type that a fetch helper returns instead of throwing.
• Explain SQL codeRanking customers by this year's spend with a LEFT JOIN, GROUP BY and RANK().
• Explain Bash codeA script that finds the 10 most common errors in a folder of logs.
• Explain C codeAn array of structs allocated with calloc, filled in, used and freed.
• Explain C++ codeA function template, a class with a destructor and a unique_ptr that changes owner.
• Explain Swift codeA to-do list with a protocol, an optional due date, closures and a key path.
• Explain Ruby codeA class that mixes in a module and Comparable, then sorts and filters with blocks.