Programming Tutorials and Coding Guides

Learn Go time formatting and parsing with the reference date 2006-01-02, RFC3339, DateOnly, time.Format, time.Parse, ParseInLocation, and timezone layouts.

Learn Go's time package with examples for time.Now, UTC, Duration, Add and Sub, Unix timestamps, time zones, Format, Parse, Sleep, Timer, and Ticker.

Convert a Go string to uint8 using strconv.ParseUint, validate the 0–255 range, and learn the difference between parsing numeric text and reading a string byte.

Learn how to use a Go struct defined in another file, import an exported struct from another package, and fix undefined errors caused by go run main.go.

Convert int to int64 and int64 to int in Go, understand 32-bit vs 64-bit int sizes, check values before narrowing, and choose the correct integer type.

Learn how to kill a process by PID in Go, stop exec.Command children, use Process.Signal vs Kill, handle timeouts with CommandContext, and avoid orphan processes.

Learn how io.ReadCloser combines Reader and Closer in Go, how to close HTTP response bodies, wrap readers with io.NopCloser, and read content with io.ReadAll.

Fix Go "package is not in GOROOT", "cannot find package", and missing module errors by checking go.mod, import paths, workspaces, dependencies, and GOPATH mode.

Use Go crypto/sha256 to hash strings and files, format SHA-256 as hexadecimal, stream large files with io.Copy, and verify known checksums.

Convert byte and []byte to integers in Go using int, strconv.Atoi, encoding/binary, varints, and big.Int, with byte order and error handling explained.

Learn how Go JSON omitempty works for zero values, pointers, slices and nested structs, how omitzero differs, and what changes with encoding/json/v2 in Go 1.27.

Learn Go for loops and for range with examples for counters, while-style loops, slices, maps, strings, integers, channels, break, continue, and modern iterators.

Convert float64 to int or int64 in Go using direct conversion or math.Round, RoundToEven, Floor and Ceil, with overflow, NaN and Inf handling.

Learn how to remove a Go module dependency, undo go get, remove Go 1.24+ tool dependencies, uninstall go install binaries, and clear the module cache.

Learn how to use os.Stat in Go to read file metadata, check whether a path exists, distinguish files and directories, handle errors, and compare Stat with Lstat.

Learn who created the Go Gopher, how Renée French's WFMU character became Go's mascot in 2009, whether it has a name, and how the artwork is licensed.

Learn structured logging in Go with Uber Zap, including Logger vs SugaredLogger, production and development loggers, fields, levels, request IDs, and configuration.

Use strings.Contains to check whether a Go string contains a substring, including case-insensitive checks, multiple values, ContainsAny, ContainsRune, and common edge cases.

Learn how to hide password input in Go using golang.org/x/term ReadPassword, detect terminals with IsTerminal, handle non-TTY input, and understand asterisk masking.

Fix Go's "go.mod file not found in current directory or any parent directory" error for existing projects, new modules, go get, workspaces, IDEs, and CI.

Learn the Go os package with practical examples for opening, creating and writing files, working with directories, file metadata, environment variables, and paths.

Fix Go's "declared and not used" and "imported and not used" compiler errors, including blank identifiers, unused return values, imports, and := shadowing.

Learn how to build a WebSocket server and client in Go using Gorilla WebSocket, send text and JSON messages, close connections, and handle common errors.

Learn how to read and parse YAML files in Go, unmarshal YAML into structs or maps, handle nested data and lists, and decode multiple YAML documents.

Learn how to use fsnotify in Go to watch files and directories, handle file events, watch one file reliably, add recursive watches, and debounce changes.

Golang Cobra tutorial with a complete go cobra example: install spf13/cobra, build subcommands, local and persistent flags, test with go run, set --version, and scaffold apps with cobra-cli.

Free Bash and shell scripting course for Linux — arguments, variables, loops, functions, arrays, real scripts, and automation patterns. 30+ hands-on lessons organized into chapters; examples tested on Bash on RHEL, …

Free, hands-on Laravel tutorial - install, routes, Eloquent ORM, Blade templates, authentication, Sanctum/Passport, validation, file storage, queues, mail, and production deployment. 40+ tested lessons.

Free, hands-on Node.js tutorial - installation, REPL, file system, child processes, Express, MongoDB, authentication, error handling, debugging, and HTTPS. 35+ runnable lessons.

Free, hands-on Pandas tutorial - DataFrame fundamentals, reading and writing CSVs, selecting, filtering, joining, grouping, reshaping, and visualizing data. 30+ examples tested on Python 3.11 + pandas 2.x.