检查JavaScript字符串是否是URL

在JavaScript中是否有一种方法来检查字符串是否是URL?

regex被排除在外，因为URL很可能写成stackoverflow;也就是说，它可能没有。com, WWW或http。

当前回答

使用纯正则表达式很难做到这一点，因为url有很多“不方便”的地方。

For example domain names have complicated restrictions on hyphens: a. It is allowed to have many consecutive hyphens in the middle. b. but the first character and last character of the domain name cannot be a hyphen c. The 3rd and 4th character cannot be both hyphen Similarly port number can only be in the range 1-65535. This is easy to check if you extract the port part and convert to int but quite difficult to check with a regular expression. There is also no easy way to check valid domain extensions. Some countries have second-level domains(such as 'co.uk'), or the extension can be a long word such as '.international'. And new TLDs are added regularly. This type of things can only be checked against a hard-coded list. (see https://en.wikipedia.org/wiki/Top-level_domain) Then there are magnet urls, ftp addresses etc. These all have different requirements.

然而，这里有一个函数可以处理几乎所有的事情，除了:

案例1。c 接受任何1-5位数的端口号接受任何扩展2-13个字符不接受ftp，磁铁等…

2019-02-10 19:51:48

其他回答

我不能评论最接近#5717133的帖子，但下面是我想出如何让@tom-gullen正则表达式工作的方法。

/^(https?:\/\/)?((([a-z\d]([a-z\d-]*[a-z\d])*)\.)+[a-z]{2,}|((\d{1,3}\.){3}\d{1,3}))(\:\d+)?(\/[-a-z\d%_.~+]*)*(\?[;&a-z\d%_.~+=-]*)?(\#[-a-z\d_]*)?$/i

2014-03-19 22:34:42

(我没有代表对ValidURL的例子发表评论;因此，把这个作为一个答案。)

虽然不鼓励使用协议相对URL(协议相对URL)，但有时确实会使用它们。要用正则表达式验证这样的URL，协议部分可以是可选的，例如:

function isValidURL(str) {
    var pattern = new RegExp('^((https?:)?\\/\\/)?'+ // protocol
        '(?:\\S+(?::\\S*)?@)?' + // authentication
        '((([a-z\\d]([a-z\\d-]*[a-z\\d])*)\\.)+[a-z]{2,}|'+ // domain name
        '((\\d{1,3}\\.){3}\\d{1,3}))'+ // OR ip (v4) address
        '(\\:\\d+)?(\\/[-a-z\\d%_.~+]*)*'+ // port and path
        '(\\?[;&a-z\\d%_.~+=-]*)?'+ // query string
        '(\\#[-a-z\\d_]*)?$','i'); // fragment locater
    if (!pattern.test(str)) {
        return false;
    } else {
        return true;
    }
}

正如其他人指出的那样，正则表达式似乎不是验证url的最佳方法。

2017-07-11 21:26:22

这是@palvo的答案的扩展。

function isValidHttpUrl(string) {
  let url;
  try {
    url = new URL(string);
  } catch (_) {
    return false;  
  }
  return (url.protocol === "http:" || url.protocol === "https:") && (url.href == string || url.origin == string);
}

试试以下方法:-

isValidHttpUrl(“https:母羊/ dsdsd”); isValidHttpUrl(“https://ewe/dsdsd”);

Chrome测试

2022-01-27 07:50:00

对已接受答案的改进…

Check for ftp/ftps as protocol Has double escaping for backslashes (\\) Ensures that domains have a dot and an extension (.com .io .xyz) Allows full colon (:) in the path e.g. http://thingiverse.com/download:1894343 Allows ampersand (&) in path e.g http://en.wikipedia.org/wiki/Procter_&_Gamble Allows @ symbol in path e.g. https://medium.com/@techytimo isURL(str) { var pattern = new RegExp('^((ft|htt)ps?:\\/\\/)?'+ // protocol '((([a-z\\d]([a-z\\d-]*[a-z\\d])*)\\.)+[a-z]{2,}|'+ // domain name and extension '((\\d{1,3}\\.){3}\\d{1,3}))'+ // OR ip (v4) address '(\\:\\d+)?'+ // port '(\\/[-a-z\\d%@_.~+&:]*)*'+ // path '(\\?[;&a-z\\d%@_.,~+&:=-]*)?'+ // query string '(\\#[-a-z\\d_]*)?$','i'); // fragment locator return pattern.test(str); }

2017-08-08 11:55:55

这里还有另一种方法。

// ***note***: if the incoming value is empty(""), the function returns true var elm; function isValidURL(u){ //A precaution/solution for the problem written in the ***note*** if(u!==""){ if(!elm){ elm = document.createElement('input'); elm.setAttribute('type', 'url'); } elm.value = u; return elm.validity.valid; } else{ return false } } console.log(isValidURL('')); console.log(isValidURL('http://www.google.com/')); console.log(isValidURL('//google.com')); console.log(isValidURL('google.com')); console.log(isValidURL('localhost:8000'));

2018-04-18 22:24:17

检查JavaScript字符串是否是URL

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