Disallow “//” in a regular expression (javascript)

Question

I would like to disallow double forward slashes (//) in my regular expression (and thus allow single /), but my solutions doesn't work.

There also has to be NO / at the beginning and ending of a string (this work!):

/^[^/][a-z0-9-/]+[^/]$$/

this allows for example example///example// but NOT/dzkoadokzd///zdkoazaz

Now I want to disallow multiple "/" after each other. I've tried this but it doesn't work (I'm new to regular expressions):

/^[^/]([a-z0-9-]+[/]{1})+[^/]$$/

Answer 1

/ is a meta character in regex. You need to escape it with a backslash ( \\/ )

/^[^\/]([a-z0-9-]+[\/]{1})+[^\/]$/

Answer 2

不知道这是否是必需条件，但是jperovic的正则表达式通过使用[^ /]可以接受任何字符，而不是斜杠/（因此它还会传递类似“ @ abcd / efgh / ijkl /＃ ”的字符串（注意@和＃），但是在正则表达式的其他部分，我们尝试将字符限制为[a-z0-9-]。如果我们想限制整个字符串的字符范围，请检查以下正则表达式。

/^[a-z0-9\-](?:[a-z0-9\-]|\/(?!\/))+[a-z0-9\-]$/

Answer 3

BTW, if you just want to test for slash at the start or end or double elsewhere:

function badSlash(s) {

  var re = /^\/|\/\/|\/$/;

  return re.test(s);
}

You can add another OR for whatever other patterns you don't want, eg

  var re = /^\/|\/\/|\/$|[^a-z0-9\/]/;