Extension of Golang function life cycle

The life cycle of a Go function covers the process from declaration to exit, but can be extended in the following ways: init() function: executed before any other function call, used to initialize global variables and other operations. defer statement: defer function calls until execution when the function exits, used to release resources or clean up.

Go function life cycle extension

Go's function life cycle starts from function declaration and ends with function exit. However, this lifecycle can be extended using theinit()function and thedeferstatement.

init()Function

init()Function is executed before any other function is called, even if it Not explicitly called. It is typically used to initialize global variables or perform other one-time operations.

package main import "fmt" var myVar string func init() { myVar = "Hello, world!" } func main() { fmt.Println(myVar) // 输出: Hello, world! }

deferStatement

deferstatement defers execution of a function call until function exit, even if an error or panic. It is usually used to release resources or clean up.

package main import "fmt" import "os" func main() { file, err := os.Open("myfile.txt") if err != nil { fmt.Println("Error opening file:", err) return } defer file.Close() // 对文件进行操作... }

Practical case

In a complex application, the extension of the function life cycle can be used to achieve the following functions:

• Use theinit()function to load configuration or connect to the database.
• Use thedeferstatement to release resources (such as file descriptors or locks) or cleanup (such as logging).
• Write a custompanic()handler to catch panic and perform graceful error handling.

By extending the function life cycle, you can write more robust and easier to maintain Go code.

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