Go Regular Expression Guide: How to Match IP Addresses

Go Language Regular Expressions Guide: How to Match IP Addresses

Introduction:
Regular expressions are a powerful tool for matching and searching for specific patterns in strings. In the Go language, you can use the built-in regexp package to implement regular expression operations. This article will introduce how to use regular expressions in Go language to match IP addresses.

IP address format:
An IP address is an address composed of 32-bit binary numbers, usually represented by four separated decimal numbers. Each decimal number ranges from 0 to 255. For example: 192.168.0.1.

Regular expression to match IP address:
In Go language, you can use regular expressions to match IP addresses. The following is an example of a regular expression that matches an IP address:

^(d{1,3}.){3}d{1,3}$

Explanation:

• ^ means matching the beginning of
• d means matching numbers
• {1,3} means matching 1 to 3 numbers
• . means matching dots (.)
• {3} means matching the previous expression 3 times
• $ means matching the end

Sample code :
The following is a sample code that uses Go language regular expressions to match IP addresses:

package main

import (
    "fmt"
    "regexp"
)

func main() {
    ip := "192.168.0.1"
    match, _ := regexp.MatchString(`^(d{1,3}.){3}d{1,3}$`, ip)
    if match {
        fmt.Println("IP地址匹配成功！")
    } else {
        fmt.Println("IP地址匹配失败！")
    }
}

Output results:

IP地址匹配成功！

Extensions:
In addition to the above sample code , you can also use other functions of the regexp package to match IP addresses. Here is a sample code that uses the regexp.FindString function to match IP addresses:

package main

import (
    "fmt"
    "regexp"
)

func main() {
    ip := "192.168.0.1"
    re := regexp.MustCompile(`^(d{1,3}.){3}d{1,3}$`)
    match := re.FindString(ip)
    if match != "" {
        fmt.Printf("匹配到的IP地址是：%s
", match)
    } else {
        fmt.Println("未匹配到IP地址！")
    }
}

Output results:

匹配到的IP地址是：192.168.0.1

Summary:
This article introduces how to use Go Language regular expressions to match IP addresses, a simple regular expression example and related code implementation are given. I hope that through the introduction of this article, readers can understand how to use regular expressions to match IP addresses in the Go language.

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