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Go Essentials

Essential Go (Golang) syntax, patterns, and best practices for building efficient applications

8 min read
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Setup & Basics

Getting started with Go

Installation & Setup

Installing Go and setting up development environment

bash
🚀 Compiled language with fast execution
📦 Built-in dependency management with go mod
🔧 Simple toolchain with go command
⚡ Static binaries for easy deployment

Basic Syntax

Go program structure and syntax

go
📝 Static typing with type inference
🎯 Simple, clean syntax without semicolons
🔧 := for short variable declarations
📦 Package-based organization

Data Types & Structures

Go data types, arrays, slices, maps, and structs

Arrays & Slices

Working with arrays and slices

go
📊 Arrays have fixed size, slices are dynamic
🔄 append() to add elements to slices
📦 make() to create slices with capacity
⚡ Slices are references to underlying arrays

Maps

Working with maps (hash tables)

go
🗺️ Hash tables with O(1) average access
🔑 Any comparable type can be a key
❌ Use delete() to remove entries
⚠️ Maps are not thread-safe by default

Structs

Defining and using structs

go
📦 Group related data with structs
🏷️ Tags for JSON/DB field mapping
🔄 Methods with value or pointer receivers
🎯 Composition over inheritance with embedding

Control Flow

Conditionals, loops, and control structures

Conditionals

If statements and switch cases

go
🎯 No parentheses needed around conditions
🔄 Switch doesn't need break (no fallthrough by default)
📦 Type switches for interface type assertion
⚡ Switch can be used without an expression

Loops

For loops and iterations

go
🔄 Only for loops (no while/do-while)
📊 range for iterating collections
🏷️ Labels for breaking nested loops
⚡ range on channels until closed

Functions

Functions, methods, and closures

Functions

Function declaration and usage

go
📦 Multiple return values for errors
🔄 defer for cleanup (LIFO order)
📝 Variadic functions with ...
⚡ Functions are first-class values

Methods

Methods on types and interfaces

go
📦 Methods attached to types with receivers
🔄 Value receivers can't modify, pointer receivers can
🎯 Go auto-dereferences and takes addresses
⚡ Methods can be on any type, not just structs

Interfaces

Interface types and polymorphism

Interfaces

Defining and implementing interfaces

go
🎯 Implicit interface implementation
📦 interface{} for any type
🔄 Type assertions and type switches
⚡ Small interfaces are better (Interface Segregation)

Concurrency

Goroutines, channels, and synchronization

Goroutines

Concurrent execution with goroutines

go
🚀 Lightweight threads managed by Go runtime
⚡ Can run millions of goroutines
🔄 Use sync.WaitGroup for synchronization
⚠️ Beware of race conditions - use channels or mutexes

Channels

Communication between goroutines

go
📡 Channels for goroutine communication
🔄 Buffered vs unbuffered channels
🎯 select for multiplexing channel operations
⏱️ Timeouts with time.After()

Error Handling

Error handling patterns and best practices

Error Handling

Working with errors in Go

go
❌ Errors are values, not exceptions
🔄 Always check returned errors
📦 Wrap errors with context using %w
🎯 errors.Is() and errors.As() for error checking

Testing

Writing and running tests

Testing

Unit tests and benchmarks

go
🧪 Built-in testing with testing package
📊 Table-driven tests for multiple cases
⚡ Benchmarks with go test -bench
📈 Coverage with go test -cover

Packages & Modules

Package management and module system

Packages & Imports

Organizing code with packages

go
📦 Packages for code organization
🔒 Capitalized names are exported
📁 internal/ for private packages
⚡ go.mod for dependency management