golang error control

Go language is an increasingly popular programming language with the characteristics of rapid development and efficient performance. It has become the preferred language for development in the Internet field. Error control is a very important aspect during the development process. The Go language provides a simple error handling mechanism to help developers better handle possible exceptions.

Classification of errors

Before discussing error handling, we need to understand the basic classification of errors in the Go language. In the Go language, errors are mainly divided into two categories: recoverable errors and unrecoverable errors.

Recoverable errors refer to errors that can be repaired or dealt with so that the program can continue to execute normally; while unrecoverable errors mean that the program cannot continue to run normally and the execution of the program needs to be terminated. Problems like memory overflow are unrecoverable errors, while problems like filename errors are recoverable.

Error handling mechanism

The Go language provides two methods for error handling: returning error information and using the panic/recover mechanism.

1. Return error message

In the Go language, the return value of a function is used to indicate whether the function is executed normally. If the function executes successfully, it returns nil, otherwise it returns a non-null pointer of type error. The error type is an interface type built into the Go language, defined as follows:

type error interface {

Error() string

}

This is a very simple interface, containing only one method , namely Error(), which returns a string describing the details of the error. So if a function's return type is error, we can judge whether its execution is normal based on whether the return value is nil.

For example, here is an example of a possible error when reading a file:

import (

"fmt"
"os"

)

func readFromFile(fname string) (string, error) {

f, err := os.Open(fname)
if err != nil {
    return "", err
}
defer f.Close()

content := make([]byte, 1024)
count, err := f.Read(content)
if err != nil {
    return "", err
}

return fmt.Sprintf("Read %d bytes: %s", count, content[:count]), nil

}

In the readFromFile() function, if an error occurs when reading the file, the error message will be returned through the error type.

2. Use the panic/recover mechanism

In the Go language, there is also a method that can interrupt program execution when an error occurs, called panic. When the program executes this function, it jumps to a mechanism similar to exception handling, which can be handled using the recover function. For example:

func readFromFilePanic(fname string) string {

f, err := os.Open(fname)
if err != nil {
    panic(err)
}
defer f.Close()

content := make([]byte, 1024)
count, err := f.Read(content)
if err != nil {
    panic(err)
}

return fmt.Sprintf("Read %d bytes: %s", count, content[:count])

}

In the readFromFilePanic() function, if an error occurs while reading the file, it will be used The panic() function interrupts the execution of the program. When this situation occurs, we can restore the execution of the program through the recover() function and continue running after recovery.

Choose when to use which method

When choosing which method to use for error handling, you need to consider the following factors:

1. Error types

If the error encountered is unrecoverable, such as memory overflow, it will be more appropriate to use the panic/recover mechanism. For recoverable errors, such as file name errors, it is more appropriate to use the method of returning error information.

2. Code clarity

When dealing with complex errors, using the method of returning error information can make the code clearer and easier to understand. When an unexplainable or difficult-to-handle problem occurs, it may be clearer to use panic/recover to terminate program execution.

3. Team collaboration

In multi-person collaboration projects, it is easier to communicate and understand among different team members by using the method of returning error information.

Error handling best practices

1. Standardization of error messages

When writing error messages, they should be as standardized as possible. Error messages should contain enough detail to facilitate error detection and handling, while remaining brief and precise. Error messages should also clearly indicate the type of error and where it occurred.

2. Don't ignore errors

You should avoid ignoring errors when writing code, even if you think the error will not affect program execution. Ignoring errors can lead to hidden problems in your code and fail to clearly demonstrate the program's behavior.

3. Error handling method of public code

For error handling involving the public code base, a unified plan should be made in the error handling method of the public code to ensure that the entire Consistency in how errors are handled across projects.

Conclusion

Error handling is a very important aspect of the Go language. When writing a program, the type and handling of errors should be carefully considered. By returning error information and using the panic/recover mechanism, program exceptions can be better handled. Good error handling mechanisms are the basis for writing high-quality and maintainable software.

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