Question

我尝试使用js验证URL。

function validateURL(url) {
  var urlregex = new RegExp("^(http:\/\/www.|https:\/\/www.|ftp:\/\/www.|www.|https:\/\/|http:\/\/){1}([0-9A-Za-z]+\.)");
  return urlregex.test(url);
}

但是我希望google.com也会通过，但它不会通过这个正则表达式。

regexp有什么问题？

我希望这些网址通过regexp传递：

http://www.google.com
http://google.com
https://www.google.com
https://google.com
google.com
www.google.com

Answer 1

请改为尝试：

function validateURL(url) {
  var urlregex = new RegExp("^((?:https?:\/\/)?(?:www\.)?[0-9A-Za-z]+\.[0-9A-Za-z]+)$");
  return urlregex.test(url);
}

“ <强>样本
http://regex101.com/r/rG8wP9

<强> OR：

function validateURL(url) {
if (/^((?:https?:\/\/)?(?:www\.)?[0-9A-Za-z]+\.[0-9A-Za-z]+)$/im.test(url)) {
    return true;
} else {
    return false;
}
}

说明：

^ assert position at start of a line
1st Capturing group ((?:https?:\/\/)?(?:www\.)?[0-9A-Za-z]+\.[0-9A-Za-z]+)
(?:https?:\/\/)? Non-capturing group
Quantifier: Between zero and one time, as many times as possible, giving back as needed [greedy]
http matches the characters http literally (case sensitive)
s? matches the character s literally (case sensitive)
Quantifier: Between zero and one time, as many times as possible, giving back as needed [greedy]
: matches the character : literally
\/ matches the character / literally
\/ matches the character / literally
(?:www\.)? Non-capturing group
Quantifier: Between zero and one time, as many times as possible, giving back as needed [greedy]
www matches the characters www literally (case sensitive)
\. matches the character . literally
[0-9A-Za-z]+ match a single character present in the list below
Quantifier: Between one and unlimited times, as many times as possible, giving back as needed [greedy]
0-9 a single character in the range between 0 and 9
A-Z a single character in the range between A and Z (case sensitive)
a-z a single character in the range between a and z (case sensitive)
\. matches the character . literally
[0-9A-Za-z]+ match a single character present in the list below
Quantifier: Between one and unlimited times, as many times as possible, giving back as needed [greedy]
0-9 a single character in the range between 0 and 9
A-Z a single character in the range between A and Z (case sensitive)
a-z a single character in the range between a and z (case sensitive)
$ assert position at end of a line
g modifier: global. All matches (don't return on first match)
m modifier: multi-line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)

Answer 2

regexp有什么问题？

这部分正则表达式：

([0-9A-Za-z]+\.)

在您的示例中，

无法与“google.com”匹配。但它与错误的域名地址匹配，例如谷歌。这样的事情：

(?:[0-9A-Za-z]+\.)+[A-Za-z]{2,}

更加正确和灵活。

Answer 3

这个正则表达式中有些功能无效。例如，在结束之后没有任何事情发生。也绝不需要{1}，因为默认情况下每个表达式匹配一次。主要问题是|因为分支不在()内，所以在每个|之后匹配重新开始

这是你的正则表达式清理。例如，将内容分组，请参阅|内的()。

isMatch = (/^(?:(?:https?|ftp):\/\/)?(?:www\.)?[0-9a-z]+\.[a-z]+/im.test(url))

javascript - url正则表达式不正确

3 个答案: