How to import and use the flag package in Go for command-line argument parsing?

To import and use the flag package in Go for command-line argument parsing, you can follow these steps:

Import the flag package in your code:

import "flag"

Define variables to store the command-line arguments. For example, if you want to accept a string argument named name and an integer argument named age, you can define the variables as follows:

var name string
var age int

Use the flag package to define the corresponding command-line flags and bind them to the variables. Use the StringVar function for string flags and the IntVar function for integer flags. For example:

flag.StringVar(&name, "name", "", "Your name")
flag.IntVar(&age, "age", 0, "Your age")

Here, the first argument is the variable to bind the flag value to, the second argument is the flag name (including any shorthand notation), the third argument is the default value, and the fourth argument is a short description of the flag.

Parse the command-line arguments using the Parse function of the flag package:

flag.Parse()

Now, you can use the variables name and age to access the parsed command-line arguments.

Here's a complete example that demonstrates how to import and use the flag package:

package main

import (
	"flag"
	"fmt"
)

func main() {
	// Define command-line flags
	var name string
	var age int
	flag.StringVar(&name, "name", "", "Your name")
	flag.IntVar(&age, "age", 0, "Your age")

	// Parse command-line arguments
	flag.Parse()

	// Use the parsed values
	fmt.Println("Name:", name)
	fmt.Println("Age:", age)
}

In this example, you can run the program with command-line arguments like -name John -age 25 to set the corresponding variables.