Coding prompts

Go through this [language] code section by section. For each part, say what it does and why it might be written that way, then point out anything that looks like a bug or a trap for future changes: [paste code]

This [language] function should [expected behaviour], but with input [example input] it returns [actual output]. Find the cause, explain it in two sentences, and show the corrected function with the changed lines marked: [paste code]

Write a [language] function called [name] that [what it does]. Inputs: [inputs and types]. Output: [output]. Handle these edge cases: [edge cases]. Add a short docstring and three example calls with their expected results.

Refactor this [language] code so it is easier to read and change, without altering its behaviour. Use clearer names, split long functions, and remove duplication. Then list each change and why it helps: [paste code]

Translate this [source language] code into idiomatic [target language], using its standard library where possible. Keep the same behaviour, and add comments wherever the two languages handle something differently, such as integer division or null values: [paste code]

Here is my schema in [database, e.g. PostgreSQL]: [paste CREATE TABLE statements]. Write a query that [what you need]. Explain the joins and filters you used, and mention any index that would make it faster on a large table.

I need a [flavour, e.g. JavaScript] regular expression that matches [what to match] but not [what to exclude]. Give the pattern, break it down piece by piece, and list sample strings with match or no match next to each.

What does this error mean in plain words? [paste error]. I'm using [language, framework and version] and it appears when I [action]. List the usual causes, what to check first, and a minimal example that reproduces the error.

Add docstrings and comments to this [language] code in the [style, e.g. Google or JSDoc] format. Explain why things are done where it isn't obvious, skip comments that only repeat the code, and don't change any logic: [paste code]

Act as a security reviewer for this [language] snippet. Look for injection, unsafe deserialisation, unchecked input, weak hashing and hard-coded secrets. Rate each finding low, medium or high, describe a realistic attack, and show the safer version: [paste code]

This [language] code is too slow when [data size or situation]: [paste code]. Explain where the time goes, estimate its complexity in big-O terms, and suggest faster approaches, starting with the simplest change that would help most.

Design REST API endpoints for [feature] in my [type of app]. For each endpoint, give the method, path, request body, response example, status codes and who may call it. Point out decisions I still need to make.

Write a [Bash, PowerShell or Python] script that [task, e.g. renames all photos in a folder by date taken]. It runs on [operating system]. Add a dry-run option that only prints what would happen, and explain how to run it.

I'm in this situation with Git: [describe what you did and what git status shows]. I want to [goal] without losing [work to keep]. Give me the commands step by step, explain what each one does, and warn me before any step that can't be undone.

I've attached a screenshot of a page layout I like. Write semantic HTML and modern CSS that reproduce its structure: header, columns, spacing and font sizes, using [plain CSS or a framework]. Use placeholder text and make it responsive for phones.

Write a README for this project based on the code and notes below. Include a one-line description, installation steps, a usage example, configuration options and how to run the tests. Mark anything you had to guess with TODO: [paste code or notes]

Explain [concept, e.g. closures or async/await] in [language] to someone who knows the basics. Use one tiny runnable example, show what it prints, then change one line and explain how the output changes.

Propose a database schema for [app or feature] that stores [the main things, e.g. users, orders and products]. Show the tables with columns, types, keys and relationships, then explain one trade-off in your design and an alternative.

Write [framework, e.g. pytest or Jest] tests for this code. Cover the normal case, boundaries, invalid input and one failure from a dependency, using mocks where needed. Name each test after the behaviour it checks: [paste code]

I want to build [project idea] with [language or stack] and I have about [hours] hours a week. Break it into milestones I can finish one at a time, list what I need to learn for each, and suggest a simple folder structure to start with.