Error Handling in Go – Custom Errors, Panic, and Recover Guide

The error Type

Go handles errors explicitly as return values, rather than using exceptions.

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

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

Custom Errors

type NotFoundError struct {
    Name string
}

func (e *NotFoundError) Error() string {
    return e.Name + " not found"
}

panic and recover

panic stops normal execution immediately, while recover can catch a panic inside a deferred function to prevent the program from crashing.

func safeDivide(a, b int) {
    defer func() {
        if r := recover(); r != nil {
            fmt.Println("Recovered from:", r)
        }
    }()
    fmt.Println(a / b) // panics if b is 0
}