正则表达式，为什么结果如下？ - Js [英] Regular expression, why the result is the following? - Js

问题描述

let text = "titanic";
let myRegex = /t[a-z]*i/; // Change this line
let result = text.match(myRegex); //gives "titani" -- why?

我尝试过：



寻找'/ t'解释。

What I have tried:

looking for the '/t' explanations.

推荐答案

因为它匹配。

*是零或更多所以ti匹配，但titani也是如此。

如果你想要最短的匹配，你必须告诉正则表达式：

Because it matches.
"*" is "zero or more" so "ti" matches, but so does "titani".
If you want the shortest match, you have to tell the regex that:

/t[a-z]*?i/

帮助构建和调试RegEx的一些有趣的链接。

以下是RegEx文档的链接：

perlre - perldoc.perl.org [ ^ ]

这是链接到帮助构建RegEx并调试它们的工具：

.NET正则表达式测试程序 - 正则表达式风暴 [ ^ ]

快速正则表达式工具 [ ^ ]

RegExr：Learn，Build，&测试RegEx [ ^ ]

在线正则表达式测试器和调试器：PHP，PCRE，Python，Golang和JavaScript [ ^ ]

这个显示RegEx是一个很好的图表，它非常有助于理解RegEx的作用： Debuggex：在线可视正则表达式测试器。 JavaScript，Python和PCRE。 [ ^ ]

此网站还在一个漂亮的图表中显示正则表达式，但无法测试与RegEx匹配的内容： Regexper [ ^ ]

Just a few interesting links to help building and debugging RegEx.
Here is a link to RegEx documentation:
perlre - perldoc.perl.org[^]
Here is links to tools to help build RegEx and debug them:
.NET Regex Tester - Regex Storm[^]
Expresso Regular Expression Tool[^]
RegExr: Learn, Build, & Test RegEx[^]
Online regex tester and debugger: PHP, PCRE, Python, Golang and JavaScript[^]
This one show you the RegEx as a nice graph which is really helpful to understand what is doing a RegEx: Debuggex: Online visual regex tester. JavaScript, Python, and PCRE.[^]
This site also show the Regex in a nice graph but can't test what match the RegEx: Regexper[^]

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