[Go] slice interfaces and types gocron source of comprehensive reading -go language

// getCommands
func getCommands() []cli.Command {
    command := cli.Command{
        Name:   "web",
        Usage:  "run web server",
        Action: runWeb,
        Flags: []cli.Flag{
            cli.StringFlag{
                Name:  "host",
                Value: "0.0.0.0",
                Usage: "bind host",
            },
            cli.IntFlag{
                Name:  "port,p",
                Value: DefaultPort,
                Usage: "bind port",
            },
            cli.StringFlag{
                Name:  "env,e",
                Value: "prod",
                Usage: "runtime environment, dev|test|prod",
            },
        },
    }

    return []cli.Command{command}
}

Those above code is very easy to understand, we need to split it into perspective
when we directly instantiate a class, if the brace row vertically, then after members inside the assignment to add a comma

    B: = Taoshihan {
        Name: "taoshihan",
    }
    fmt.Println(b.Name)

 

Define an interface, the interface inside a member method

type Flag interface {
    GetName() string
}

 

Define another type, which happens to have this method, then you can think that this type implements the interface

type StringFlag struct {
}
func (t StringFlag) GetName() string {
    return "taoshihan"
}

Flag this time if you define the type of variable, StringFlag also be assigned in the past

was a Flag
a = StringFlag{}
a.GetName()

 

Then back to the original logic of the code, using the following if this is very easy to understand manner

was myflag [] Flag
myflag = append(myflag, StringFlag{}, StringFlag{})

command := Command{
    Flags: myflag,
}

Complete source code:

package main

import "fmt"

type Flag interface {
    GetName() string
}

type Command struct {
    Flags []Flag
}
type StringFlag struct {
}

func (t StringFlag) GetName() string {
    return "taoshihan"
}

type Taoshihan struct {
    Name string
}

func main() {
    // var a Flag
    // a = StringFlag{}
    // a.GetName()
    // b := Taoshihan{
    //     Name: "taoshihan",
    // }
    // fmt.Println(b.Name)

    was myflag [] Flag
    myflag = append(myflag, StringFlag{}, StringFlag{})

    command := Command{
        Flags: myflag,
    }
    for _, p := range command.Flags {
        fmt.Println(p.GetName())
    }
}