Error Handling in Go

Error handling in Go is simple and idiomatic, using explicit error checks. Go's clarity makes managing errors straightforward. Here's an example with custom error types and error wrapping.

Example: Custom Error Types and Error Wrapping

package main

import (
    "errors"
    "fmt"
)

type CustomError struct {
    Code int
    Msg  string
}

func (e *CustomError) Error() string {
    return fmt.Sprintf("Code: %d, Msg: %s", e.Code, e.Msg)
}

func riskyOperation() error {
    return &CustomError{Code: 404, Msg: "Resource not found"}
}

func main() {
    err := riskyOperation()

    if err != nil {
        fmt.Println("Error occurred:", err)
        var customErr *CustomError
        if errors.As(err, &customErr) {
            fmt.Printf("Custom Error - Code: %d, Msg: %s\n", customErr.Code, customErr.Msg)
        }
    }

}

Explanation

1. Custom Error Type: Define a CustomError struct implementing the Error method.

2. Risky Operation: The riskyOperation function returns a CustomError.

3. Error Handling: In main, check for errors and use errors.As to handle the custom error type.

By following these patterns, you can create clear and maintainable error handling in your Go applications.