How to use regular expressions to verify email addresses in golang

How to use regular expressions to verify email addresses in golang

Golang is a powerful, easy-to-learn and easy-to-use programming language. It supports a built-in regular expression library, which can easily verify email addresses. verification.

This article will introduce how to use golang's built-in regular expression library to verify email addresses.

The basic idea of ​​​​regular expression verification of email addresses is as follows:

1. The email address consists of the user name and domain name
2. The user name can contain letters, numbers, underscores, and dots , but it cannot end with a dot or an underscore, and there cannot be more than one consecutive dot.
3. The domain name must contain a . and must not end with .

The regular expression for verifying the email address is as follows:

^[a-zA-Z0-9_-]+(.[a-zA-Z0-9_-]+)*@[a-zA-Z0-9_-]+(.[a-zA-Z0-9_-]+)+$

The specific instructions are as follows:

1. ^ represents the beginning of the string
2. [a-zA-Z0-9_-] represents matching at least one letter, number, underscore or hyphen
3. (.[ a-zA-Z0-9_-] )* means match zero or more matching groups followed by a dot and at least one letter, number, underscore, or hyphen.
4. @ represents the @ symbol in the email address
5. [a-zA-Z0-9_-] matches at least one letter, number, underscore, or hyphen
6. (.[ a-zA-Z0-9_-] ) means match at least one dot and at least one letter, number, underscore, or hyphen, possibly followed by multiple missed dots and letters, numbers, underscores, or hyphens.
7. $ represents the end of the string.

The following is a complete golang code example showing how to use this regular expression to verify email addresses.

package main

import (

"fmt"
"regexp"

)

func main() {

email := "myemail@gmail.com"
if IsEmailValid(email) {
    fmt.Println("Valid email address")
} else {
    fmt.Println("Invalid email address")
}

}

func IsEmailValid(email string) bool {

emailRegex := "^[a-zA-Z0-9_-]+(\.[a-zA-Z0-9_-]+)*@[a-zA-Z0-9_-]+(\.[a-zA-Z0-9_-]+)+$"
match, _ := regexp.MatchString(emailRegex, email)
return match

}

In this example, we define a function called IsEmailValid, which uses the MatchString function in golang's regular expression library regexp to verify that a given email address complies with the rules. If the verification is successful, it returns true, otherwise it returns false.

Finally, we can call the IsEmailValid function to verify the email address and output the verification result. In this example, we verified the email address myemail@gmail.com and the results show that the address is valid.

To sum up, using golang’s built-in regular expression library can easily achieve effective verification of email addresses. Just put the verification logic into a function and then use the MatchString function to verify. Moreover, on this basis, it can also be extended to implement more complex verification logic.

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