How to use regular expressions in golang to verify whether the bank card number is in the blacklist

With the continuous advancement of technology, electronic payment has become an indispensable part of daily life. In the process of adopting electronic payment, bank card numbers have naturally become one of the key information carrying wealth. However, bad actors also use this important information to commit fraud, theft and other activities. In order to ensure the security of the payment process, banks and various financial institutions have imposed some regulations and restrictions on bank card numbers, and have blacklisted some card numbers that are considered unsafe. In this case, how to use regular expressions to verify whether the bank card number is in the blacklist is crucial.

Go language is one of the most popular programming languages ​​in recent years. Its simplicity, efficiency and security make it widely used in web development, system programming and other fields. In the Go language, there is a built-in regular expression package regexp, which we can use to verify whether the bank card number is in the blacklist.

First, we need to extract the bank card numbers in the blacklist in the form of regular expressions, and then use the MatchString method of the regexp package in the Go language to match Whether the bank card number that needs to be verified matches any regular expression in the blacklist. The following is a sample code:

package main

import (
    "fmt"
    "regexp"
)

func main() {
    // 黑名单中的银行卡号以正则表达式的形式存储
    blacklist := []string{
        "^62509356[0-9]*$",
        "^62179011[0-9]*$",
        "^60336701[0-9]*$",
        "^62350600[0-9]*$",
    }

    // 待验证的银行卡号
    cardNumber := "6250935688888888"

    // 利用正则表达式验证银行卡号是否在黑名单中
    for _, pattern := range blacklist {
        if matched, _ := regexp.MatchString(pattern, cardNumber); matched {
            fmt.Println("银行卡号在黑名单中")
            return
        }
    }

    fmt.Println("银行卡号不在黑名单中")
}

In the above code, we store the bank card numbers in the blacklist in the form of a string array, and each string represents a regular expression. cardNumber The variable represents the bank card number to be verified. We traverse the entire blacklist and pass each regular expression to the MatchString method one by one for matching. If a regular expression successfully matches the bank card number to be verified, the bank card number is considered to be in the blacklist.

It should be noted that when the number of regular expressions in the blacklist is relatively large, using the MatchString method for traversal matching may cause performance problems. If we need to optimize performance, we can merge all regular expressions into one large regular expression, then use the regexp.MustCompile method to compile, and finally use the MatchString method to compile match. The following is a sample code:

package main

import (
    "fmt"
    "regexp"
    "strings"
)

func main() {
    // 黑名单中的银行卡号以正则表达式的形式存储
    blacklist := []string{
        "^62509356[0-9]*$",
        "^62179011[0-9]*$",
        "^60336701[0-9]*$",
        "^62350600[0-9]*$",
    }
    blacklistPattern := strings.Join(blacklist, "|")

    // 编译正则表达式
    regex := regexp.MustCompile(blacklistPattern)

    // 待验证的银行卡号
    cardNumber := "6250935688888888"

    // 利用正则表达式验证银行卡号是否在黑名单中
    if matched := regex.MatchString(cardNumber); matched {
        fmt.Println("银行卡号在黑名单中")
    } else {
        fmt.Println("银行卡号不在黑名单中")
    }
}

In the above code, we merge all regular expressions into one large regular expression through the strings.Join method, and use regexp .MustCompile method to compile. The compiled regular expression can be passed directly to the MatchString method for matching, without having to iterate through each regular expression one by one.

In short, using regular expressions in Go language to verify whether a bank card number is in the blacklist is a very important task. By writing regular expressions and using the regexp package in the Go language for verification, you can effectively avoid financial losses caused by criminals using bank card numbers.

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