Golang Subtract Time: time.Now Minus Duration Examples
Subtract time in Go with time.Add and negative durations, time.Now minus 1 hour, time.Sub for differences between two time.Time values, AddDate for calendar days and months, and common mistakes.
Golang Switch Case Statement: Examples, Multiple Cases, and Type Switch
Use the switch statement in Go for switch case and default, comma-separated cases, expressionless switch, initial statements, type switch on any, fallthrough, and patterns that replace long if-else chains.
Find GCD in JavaScript (Euclidean algorithm, BigInt, mathjs)
GCD in JavaScript (greatest common divisor, not denominator): Euclidean gcd recursive and iterative with Math.abs for negatives, reduce fold for many numbers, BigInt gcd without mixing Number, optional mathjs variadic …
Golang Function as Parameter Explained with Examples
Pass functions as parameters in Go: func types, named and anonymous arguments, callbacks, defined function types, method values and expressions, errors, and when to prefer an interface or generics.
Install Go on Ubuntu: apt, snap, or official tarball (with checksum)
Installing golang on Ubuntu: apt golang-go, snap install go --classic, official go.dev/dl tarball with sha256 verify, optional build-from-source with bootstrap Go, amd64 and arm64, PATH and GOBIN, go version, go mod init …
Go get private repository: GOPRIVATE, SSH, HTTPS, and go mod private repo
Go get private repository and golang private repo with modules: GOPRIVATE, GONOPROXY, GONOSUMDB, SSH insteadOf HTTPS, PAT and .netrc, go no secure protocol found for repository, terminal prompts disabled, GitHub GitLab …
Golang MongoDB tutorial: driver v2, BSON, ObjectId, and CRUD
Step-by-step golang and mongodb with go.mongodb.org/mongo-driver/v2: URI connect Ping, implicit create database, BSON golang bson ObjectId, CRUD, bson regex golang, dates; legacy mgo note.
Golang methods: receivers, struct methods, and interfaces
Golang method and go methods: value vs pointer receivers, golang struct methods and calls, methods on defined types, method sets and interfaces; same-package rules and when Go adjusts & for you.
Enums in Go with iota, named types, and String()
Model a golang enum as a named integer type with const iota values, optional String and fmt.Stringer, validation helpers, and JSON encode or decode via maps or custom MarshalJSON when strings cross APIs.
Encrypt and decrypt strings in Go with AES-GCM
Encrypt and decrypt byte slices or strings in Go using AES-256 with GCM for confidentiality and integrity, a random nonce per message, and base64 for storage; extend the same pattern to files by reading and writing raw …
Smaller Go Docker images with multi-stage builds
Shrink a Go service image with Docker multi-stage builds: compile in a golang image, then copy only the static binary into a minimal runtime such as Alpine so the final image stays small for deploy and bandwidth.
Golang lint and go vet: golangci-lint, formatting, and nolint:gosec
Golang linting with go vet and golangci-lint; go lint command meaning versus go vet; golang linter setup; nolint:gosec and targeted nolint directives; gofmt goimports; golint deprecated.
Golang get IP address: local IPv4/IPv6, hostname, and Linux interfaces
Golang get ip address and golang get local ip: net.InterfaceAddrs and Interfaces for linux get local ip, golang get hostname with LookupHost, go get ip address heuristics, golang get local ip address without loopback, …
Golang URL query parameters: url.Values, encoding, and reading requests
Golang url values and url.Values.Encode to add query parameters; golang http request parameters from r.URL.Query; golang url parameters with Set and Add; avoid raw fmt.Sprintf for untrusted strings. Related HTTP overview …
Golang HTTP POST JSON: send a post request with a JSON body in Go
Golang http post json and golang post request with json body using net/http: http.NewRequest with bytes.Reader, Content-Type application/json, json.Marshal, and a minimal server decode with json.Decoder; httptest example …
Golang performance and speed: how Go compares and why it is fast
Golang performance versus Java, Python, Node.js, and C; why the Go language feels fast for servers; golang performance benchmark with go test; golang closure performance basics; links to official docs and community …
Go pass by value or reference: pointers, slices, and maps in Go
Is go pass by value or reference: Go passes arguments by value; golang pass by reference means passing pointers. go pass by value for structs; slices and maps alias shared data. golang pass by reference or value, golang …
Golang print struct: fmt verbs, pretty JSON, and type names
Print struct golang and go print struct with fmt.Printf verbs (%v %+v %#v), golang pretty print struct via encoding/json, golang print type of variable with %T and reflect.TypeOf, fmt.Stringer, and optional go-spew.
Golang queue: FIFO slice, container/list, and channels
Golang queue implementation for FIFO: slice append and reslice, golang fifo queue memory notes, container/list, buffered channel go queue, generics helpers, peek and empty checks, concurrency hints, and links to channels …
Golang prompt and interactive CLI: stdin, passwords, promptui, survey
Golang interactive CLI and golang prompt for input with bufio; golang.org/x/term ReadPassword with os.Stdin.Fd; promptui golang and survey; go-prompt (c-bata); notes on TTYs and cross-platform terminals.
Golang read file, update in place, and overwrite safely
Golang read file and golang read entire file with os.ReadFile; golang open file and os.OpenFile flags; golang overwrite file and append; update one field of big file golang via temp file rename or streaming; WriteAt …
Golang multiline string and reading multiple lines from stdin
Golang multiline string with raw backticks and escapes; golang read stdin and golang read line from stdin using fmt.Scan tokens, bufio.Reader ReadString, and bufio.Scanner; EOF and token size notes; not golang multiline …
Golang random bool and random boolean: math/rand and crypto/rand
Golang random bool and golang random boolean with math/rand Intn and Float64, golang rand local source for tests, random boolean generator patterns in Go, and crypto/rand when you need unpredictable bits—not Python or …
Delete keys from a map in Go with delete()
Remove entries from a map in Go with the built-in delete(map, key); deleting a missing key is safe; use the comma-ok form first when you want to log or branch on absent keys.
Golang user input: Scan, Scanf, and bufio for stdin
How to take input in golang and golang get user input from stdin: fmt.Scan Scanln Scanf for typed tokens, golang read input with bufio; go read user input and how to get user input in go with line-based reads; input …
Golang print type: %T, reflect, and type switches
Go print type and golang print type of variable with fmt %T; golang get type via reflect.TypeOf and Kind; pointers, interface{}, and nil; type switches; golang print object as dynamic concrete type.
Golang panic and recover: defer, stack unwinding, and catch-style recovery
Golang panic and go panic: how unwinding works with defer; golang recover from panic and go recover panic in a deferred function (go catch panic / golang catch panic pattern); panic vs errors and os.Exit; logging with …
Golang math pow: power in Go with math.Pow
golang math pow and go math.pow with math.Pow(x,y float64); golang power examples, integer casts and overflow pitfalls, special cases from pkg.go.dev, and alternatives for exact integer exponentiation.
Golang pad string and numbers: fmt padding, leading zeros, and floats
Golang string padding and go padding with fmt.Printf and Sprintf: golang pad string with spaces or zeros, golang format int with leading zeros, golang format float width and precision; optional golang.org/x/text/number.
Golang get current directory, cwd, and path: os.Getwd, Getwd, Executable
Golang get current directory and golang get cwd: os.Getwd for golang get current working directory and golang get pwd, golang print current directory, golang get current path with filepath.Abs, go get current directory …