我不知道发生了什么。使用golang的regexp库时,相同的函数相同的输入返回不同的结果。
package main import ( "fmt" "regexp" ) type paymentnetworkdata struct { regex string name string } var payment_networks = map[string]paymentnetworkdata{ "mastercard": { regex: "^5[1-5][0-9]{14}|^(222[1-9]|22[3-9]\\d|2[3-6]\\d{2}|27[0-1]\\d|2720)[0-9]{12}$", name: "mastercard", }, "visamaster": { regex: "^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14})$", name: "visamaster", }, } func resolvepaymentnetwork(cardin string) string { paynet := "unknown" for _, v := range payment_networks { regex := regexp.mustcompile(v.regex) if regex.matchstring(cardin) { paynet = v.name } } return paynet } func main() { in := "5103901404433835" for i := 1; i < 100; i++ { paynet := resolvepaymentnetwork(in) fmt.println("payment network is: ", paynet) } }
输入:5103901404433835
正则表达式:
mastercard: ^5[1-5][0-9]{14}|^(222[1-9]|22[3-9]\\d|2[3-6]\\d{2}|27[0-1]\\d|2720)[0-9]{12}$ visamaster: ^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14})$
go 语言输出:
payment network is: visamaster payment network is: mastercard payment network is: mastercard payment network is: visamaster payment network is: visamaster payment network is: visamaster payment network is: visamaster payment network is: visamaster payment network is: visamaster
我使用 nodejs 测试了相同的代码,在本例中结果始终相同。
js 输出:
Payment Network is: VisaMaster Payment Network is: VisaMaster Payment Network is: VisaMaster Payment Network is: VisaMaster Payment Network is: VisaMaster Payment Network is: VisaMaster Payment Network is: VisaMaster Payment Network is: VisaMaster Payment Network is: VisaMaster Payment Network is: VisaMaster
- go 代码演示:https://go.dev/play/p/up4g0jowlv_l
- js 代码演示:https://playcode.io/1450178
正确答案
您的代码有几个问题:
- 没有明显原因使用
map
, - 两个正则表达式都与提供的卡号匹配。
这些问题,以及通过映射迭代不能保证产生相同序列的事实,导致函数非幂等。
这是更正后的代码:
package main import ( "fmt" "regexp" ) type PaymentNetworkData struct { Regex *regexp.Regexp Name string } var PAYMENT_NETWORKS = [2]PaymentNetworkData{ { Regex: regexp.MustCompile("^(?:5[1-5][0-9]{14}|(?:222[1-9]|22[3-9]\\d|2[3-6]\\d{2}|27[0-1]\\d|2720)[0-9]{12})$"), Name: "Mastercard", }, { Regex: regexp.MustCompile("^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14})$"), Name: "VisaMaster", }, } func resolvePaymentNetwork(cardIn string) string { for _, v := range PAYMENT_NETWORKS { if v.Regex.MatchString(cardIn) { return v.Name } } return "Unknown" } func main() { in := "5103901404433835" for i := 1; i < 100; i++ { payNet := resolvePaymentNetwork(in) fmt.Println("Payment Network is: ", payNet) } }
它使用数组而不是映射来保证顺序。
此外,我还更改了您的结构,使其仅编译一次正则表达式。
每次输出payment network为:mastercard
。
演示此处。
注意,它仍然使用相同的正则表达式(由 评论中的@wiktorstribiżew)。它们看起来不太好,尤其是这部分 (?:4[0-9]{12}(?:[0-9]{3})?
- 它也会匹配 13 位数字。
您最好检查卡号的预期格式,并相应地更正表达式。
The above is the detailed content of Golang regexp MatchString() is not idempotent. For more information, please follow other related articles on the PHP Chinese website!

Article discusses iterating through maps in Go, focusing on safe practices, modifying entries, and performance considerations for large maps.Main issue: Ensuring safe and efficient map iteration in Go, especially in concurrent environments and with l

The article discusses creating and manipulating maps in Go, including initialization methods and adding/updating elements.

The article discusses differences between arrays and slices in Go, focusing on size, memory allocation, function passing, and usage scenarios. Arrays are fixed-size, stack-allocated, while slices are dynamic, often heap-allocated, and more flexible.

The article discusses creating and initializing slices in Go, including using literals, the make function, and slicing existing arrays or slices. It also covers slice syntax and determining slice length and capacity.

The article explains how to create and initialize arrays in Go, discusses the differences between arrays and slices, and addresses the maximum size limit for arrays. Arrays vs. slices: fixed vs. dynamic, value vs. reference types.

Article discusses syntax and initialization of structs in Go, including field naming rules and struct embedding. Main issue: how to effectively use structs in Go programming.(Characters: 159)

The article explains creating and using pointers in Go, discussing benefits like efficient memory use and safe management practices. Main issue: safe pointer use.

The article discusses the benefits of using Go (Golang) in software development, focusing on its concurrency support, fast compilation, simplicity, and scalability advantages. Key industries benefiting include technology, finance, and gaming.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Zend Studio 13.0.1
Powerful PHP integrated development environment

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

SublimeText3 English version
Recommended: Win version, supports code prompts!
