Defer behavior

A interesting form to implement defer closing or cleaning method of a process is using the example above.

The code in defer will be evaluated and executed before the Close method. This allow a initialization of the process and the Close method will be executed when the method ends. Check this out.

Go

package main

import "fmt"

type (
    Service struct {
        name string
    }
)

func NewService(name string) *Service {
    fmt.Printf("Creating new service %s\n", name)
    return &Service{name: name}
}

func (s *Service) DoSomething() {
    fmt.Printf("Doing something on service %s\n", s.name)
}

func (s *Service) Close() {
    fmt.Printf("Closing service %s\n", s.name)
}

func main() {
    defer NewService("test_defer").Close()

    fmt.Println("START MAIN")
    fmt.Println("END MAIN")
}

Bash

❯ go run defer_t.go
Creating new service test_defer
START MAIN
END MAIN
Closing service test_defer

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Last update: September 18, 2024
Created: September 18, 2024