What is the difference between error and exception?

Question

Accepted Answer

**error** — Go interface for expected failures. **Exception** — not in Go.

**Error interface:**
```go
type error interface {
    Error() string
}
```

**Creating errors:**
```go
var ErrNotFound = errors.New("not found")

type APIError struct {
    Code int
    Msg  string
}

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

**Error handling:**
```go
if errors.Is(err, ErrNotFound) {
    // handle
}

var apiErr *APIError
if errors.As(err, &apiErr) {
    fmt.Println(apiErr.Code)
}
```

**Common mistakes:**
- Ignoring errors.
- Not wrapping errors.
- Using `==` instead of `errors.Is()`.
- Creating error strings with capitals.
- Overusing panic.

Go: What is the difference between error and exception?