Detailed explanation of golang's error output

Go is a rapidly growing programming language that provides many useful tools and libraries to help write efficient, clear, and easy-to-maintain code. However, during the development process, errors will inevitably be encountered. This article will introduce golang's error output and how to better understand and debug these errors.

In the Go language, errors exist as a type. This type is called error. This type of usage is a characteristic of Go programming. In fact, the error handling mechanism in Go greatly contributes to the robustness and maintainability of the code.

In Go, errors are represented in the form of interfaces. The standard library package's errors, custom error types, and many other packages implement this interface. The error interface has only one method: Error() string, which returns error description information. In actual use, you need to pay attention to the fact that the returned error value is not empty, which means an error has occurred.

Let’s look at an example:

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

func main() {
    res, err := divide(4, 0)
    if err != nil {
        fmt.Println(err)
        return
    }
    fmt.Println(res)
}

Run the above code, the output result is:

division by zero

When we call divide(4, 0) , since b is equal to 0, so this function returns an error value that is not empty. In the function, we use the New function in the errors package to create a new error. In the main function, we first check whether the return value is empty, and if not, output an error message.

Although the way errors are generated and handled may seem redundant in this simple example, error handling is very important in complex programs. Ignoring errors may lead to unmaintainability of the program. Of course, the error handling mechanism of the Go language itself is not perfect, but it can alleviate the difficulty of errors to some extent.

In addition, the powerful error handling mechanism of the Go language also provides developers with some additional tools and techniques. For example, if you are writing a network application, you can use Go's net package to implement HTTP communication. If the code encounters an error, the net package will return an error value, and you can use the "wait a while before the connection is closed" algorithm to try to mitigate the impact of these errors.

On the other hand, if you are developing a web application, you can use the "rollback failed request" mechanism to handle errors. This mechanism takes advantage of the Go language's exception handling mechanism, which can set multiple recovery points on the function call stack. If one request fails, you can use the recovery point mechanism to roll back all requests and retry them.

In short, error handling is an essential aspect of any program. Handling errors in the Go language is very convenient, and it allows us to have good control over the robustness and maintainability of the code. In addition, the error handling mechanism of the Go language also provides developers with some useful tools and techniques, allowing us to better discover, understand and solve various errors. Therefore, if you plan to use the Go language to develop applications, it is especially important that you have a good grasp of the error handling mechanism.

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