Error Handling

Relax. We'll talk through this in plain words — no textbook voice.

Instead of exceptions, Go's normal style is to return an error value and have the caller check it. This approach keeps errors from hiding — you can see them clearly right in the code flow.

package main

import (
    "errors"
    "fmt"
)

func divide(a int, b int) (int, error) {
    if b == 0 {
        return 0, errors.New("cannot divide by zero")
    }
    return a / b, nil
}

func main() {
    result, err := divide(10, 0)
    if err != nil {
        fmt.Println("Error:", err)
        return
    }

    fmt.Println("Result:", result)
}

divide function returns a result and an error. When there's no error, it returns nil; when there is one, it returns an error value carrying a message.

You should see

Error: cannot divide by zero

Info

if err != nil might look repetitive once you notice it everywhere, but it's an important style for keeping Go code readable.

Easy traps

Ignoring errors can lead to serious production bugs. At the very least, log it, show a user-friendly message, or pass it back to the caller.