Go Basics

Introduction to Go Installing Go Go Syntax Go Variables Go Data Types Go Constants Go Operators Go Comments Go Keywords Go Identifiers Go Packages Go Import Statement Go Main Function Go Print Functions

Control Structures

Go If-Else Statements Go Switch Statement Go For Loop Go Range Go Break and Continue Go Defer Go Panic and Recover

Functions

Go Function Declaration Go Function Parameters Go Return Values Go Multiple Return Values Go Named Return Values Go Variadic Functions Go Anonymous Functions Go Closures Go Recursion

Data Structures

Go Arrays Go Slices Go Maps Go Structs Go Pointers Go Type Assertions Go Type Switches

Object-Oriented Programming

Go Methods Go Interfaces Go Embedding Go Composition Go Polymorphism

Concurrency

Go Goroutines Go Channels Go Select Statement Go Buffered Channels Go Channel Synchronization Go Channel Directions Go WaitGroups Go Mutexes Go Atomic Operations

Error Handling

Go Error Interface Go Creating Custom Errors Go Error Wrapping Go Error Handling Best Practices

File Handling

Go File Operations Go Reading Files Go Writing Files Go File Permissions

Testing

Go Testing Package Go Unit Testing Go Benchmark Testing Go Test Coverage Go Table-Driven Tests

Standard Library

Go fmt Package Go io Package Go os Package Go strings Package Go time Package Go math Package Go sort Package Go encoding/json Package Go net/http Package

Advanced Topics

Go Reflection Go Context Go Generics Go Memory Management Go Garbage Collection Go Race Detector Go Assembly Go cgo Go Profiling Go Cross-Compilation

Best Practices

Go Code Organization Go Error Handling Patterns Go Naming Conventions Go Documentation Go Performance Optimization Go Idiomatic Go Go Project Structure

Tools and Ecosystem

Go Modules Go Workspaces Go Command-Line Tools Go Linters Go Formatters Go Dependency Management Go Build Tags Go Generate

Go Return Values

Return values are a fundamental concept in Go programming. They allow functions to send data back to the caller, enabling modular and reusable code.

Basic Syntax

In Go, functions can return zero or more values. The return type is specified after the function parameters:

func functionName(parameters) returnType {
    // function body
    return value
}

Single Return Value

For a single return value, simply declare the type and use the return keyword:

func add(a, b int) int {
    return a + b
}

Multiple Return Values

Go supports returning multiple values from a function, a powerful feature for error handling and complex operations:

func divide(a, b float64) (float64, error) {
    if b == 0 {
        return 0, errors.New("division by zero")
    }
    return a / b, nil
}

This example demonstrates how to return both a result and an error, a common pattern in Go.

Named Return Values

Go allows you to name return values in the function signature. This can improve code readability and simplify the return statement:

func rectangle(width, height float64) (area, perimeter float64) {
    area = width * height
    perimeter = 2 * (width + height)
    return // naked return
}

Named return values are initialized to their zero values and can be directly used in the function body.

Best Practices

Use multiple return values for error handling
Keep the number of return values reasonable (usually 2-3 at most)
Consider using named return values for complex functions
Always handle errors returned by functions

Related Concepts

To deepen your understanding of Go functions and return values, explore these related topics:

Mastering return values is crucial for writing efficient and idiomatic Go code. Practice using different return patterns to enhance your Go programming skills.