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:

• Go Function Declaration
• Go Multiple Return Values
• Go Named Return Values
• Go Error Handling Best Practices

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