try-catch-finally in Golang exception handling

try-catch-finally in Go is used for exception handling. The syntax is: try: contains the code that needs to handle exceptions. If an exception occurs, it will immediately go to catch or finally. catch: Handle the exception thrown in try. If there is no exception, it will not be executed. finally: Will be executed regardless of whether there is an exception, often used to clean up resources.

try-catch-finally in Golang exception handling

In the Go language, the try-catch-finally statement is used Handle exceptions. Here is the syntax:

func try() {
    defer recover() // 可选，用于捕获恐慌异常
    ... // 你的需要处理异常的代码
}

try

try The block contains the code that needs to handle the exception. If an exception occurs, the statements in the try block will immediately stop execution and execution flow will go to the catch block or the finally block. The

catch

catch block is used to handle exceptions thrown in the try block. If the code in the try block does not throw an exception, the catch block will not be executed.

catch The syntax of the block is:

func catch() {
    r := recover() // 捕获 `try` 块中的恐慌异常
    ... // 处理异常的代码
}

finally

##finally block regardless of try block whether It will be executed if an exception is thrown. It is typically used to clean up resources or perform other finishing operations.

finally The syntax of the block is:

func finally() {
    ... // 清理资源或执行其他收尾操作
}

Practical case

The following is an example of handling file read exceptions:

import (
    "fmt"
    "io/ioutil"
)

func readFile(filename string) {
    defer recover()

    contents, err := ioutil.ReadFile(filename)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(contents))
}

func main() {
    readFile("existing_file.txt")
    readFile("non_existing_file.txt")
}

In this example, the

try block contains the code to read the file existing_file.txt. If the file exists and can be read successfully, the try block will execute normally and the contents will be printed to the console. The

catch block is used to handle errors that may occur in the try block. If the file does not exist or cannot be read, the try block will throw an exception and execution will go to the catch block. In the catch block, the exception is caught and printed to the console. The

finally block is optional, but it can be used to perform cleanup operations such as closing a file handle.

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