Error handling

Context

Go uses explicit error handling. Functions that can fail return an error as the last return value. Callers must check the error. The errors package provides errors.New to create simple error messages, and fmt.Errorf allows formatting.

Example

A function that divides two integers, returning an error for division by zero.

Code example

package main

import (
    "errors"
    "fmt"
)

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

func main() {
    result, err := divide(10, 2)
    if err != nil {
        fmt.Println("Error:", err)
    } else {
        fmt.Println("Result:", result)
    }

    result, err = divide(5, 0)
    if err != nil {
        fmt.Println("Error:", err)
    } else {
        fmt.Println("Result:", result)
    }
}

Output

Result: 5
Error: division by zero

Useful links

• Go by Example: Errors
• Go blog: Error handling and Go