How to handle exceptions in Go language?

Exception handling is a very important part of the Go language, and it is also an important way to write robust code. In Go, exceptions are called panics and can be handled with the recover() method.

The basic concept of Panic

Panic is a mechanism for throwing exceptions in the Go language, which is similar to throw or raise in other programming languages. When an unrecoverable error occurs in the program, panic is triggered and the execution of the program is terminated. In this case, you need to use recover() to catch the panic and perform the necessary cleanup work, or better yet, resume the execution of the program.

Syntax

The syntax of Panic is very simple, just use the panic() method. For example:

panic("Something went wrong")

After calling the panic method, the program will stop execution immediately and subsequent statements will not be executed. At the same time, the panic method can accept any type of parameters.

How to deal with Panic

What should I do if I encounter panic in the program? If the panic is not handled, the program will exit directly, which will have a great impact on the user experience and business logic. Therefore, you need to use the recover() method to handle panic.

In Go, the recover() method can capture panic and resume program execution to a certain extent. The recover() method is often used in conjunction with the defer statement.

The following is the basic syntax of recover:

func recover() interface{}

The usage is as follows:

1. Call in the defer statement recover()

defer func() {

if recover() != nil {
    fmt.Println("Recovered from panic")
}

}()

2. Call recover() in the function

func cleanup() {

if r := recover(); r != nil {
    fmt.Println("Recovered from panic")
}

}

func test() {

defer cleanup()
panic("Something went wrong")

}

In the above code, in the test() function The panic() method is called in , triggering panic, but because the cleanup() function is called in the defer statement, the recover() method is called in the cleanup() function. Therefore, when the program reaches the panic() method, execution will be suspended, and then the cleanup() function will be executed to capture the panic and perform necessary processing, and finally resume the execution of the program.

It is worth noting that if the recover() method does not detect a panic when it is called, it will return nil.

In some cases, recover() should be used in a defer statement. For example, in a server-side application, if the program panics, the panic should be caught and an error message returned to the client rather than exiting the program directly.

Summary

As a way of writing robust code, exception handling plays an important role in the Go language. It allows the program to keep running and as expected when encountering unpredictable errors. method to execute. Through the panic and recover methods, exceptions can be handled without the program exiting, making the program more stable and readable.

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