Javascript替换为regex不能正常工作

I'm trying to validate a name with regex, the regex stops the user from entering 2 spaces or dots in a row.

我试图用regex验证一个名称，regex阻止用户在一行中输入两个空格或点。

This is my code:

这是我的代码:

function test(input) {
  var regex = /^[A-Za-z]+\.{0,1}\s{0,1}$/;
  input.value = input.value.replace(regex, "");
}

<input id="txt_NomCandidato" onkeyup="test(this);" type="text" class="form-control" name="txt_Nom">

At the moment I want to enter a letter, I cant I don't know why, I hope you guys can help.

现在我想写一封信，我不能我不知道为什么，我希望你们能帮忙。

EDIT: Name only contains letters, not numbers.

编辑:名字只包含字母，不包含数字。

6 个解决方案

#1

The following regex should work for you: /[^a-zA-Z. ]|\.(?=\.)|\s(?=\s)/g

以下正则表达式应该为你工作:/[^ a-zA-Z。(? = \]| \。)| \ s(? = \ s)/ g

• [^a-zA-Z. ]+ Limits all allowed characters to a-z, A-Z, dots, or spaces
• [^ a-zA-Z。+将所有允许的字符限制为a-z、a-z、点或空格
• \.(?=\.) Limits it to only allow one dot in a row
• (? = \ \。)限制它只允许一行中有一个点
• \s(?=\s) Limits it to only one space in a row
• (?=\s)把它限制在一行中只有一个空间。

Each of these are separated by | (the or condition)

每一个都被| (or条件)分开

function test(input) {
  var regex = /[^a-zA-Z. ]|\.(?=\.)|\s(?=\s)/g;
  input.value = input.value.replace(regex, "");
}

<input id="txt_NomCandidato" onkeyup="test(this);" type="text" class="form-control" name="txt_Nom">

#2

Your regex seems correct (it matches any string with no more than 1 space or 1 dot together), but your the logic in your function seems wrong.

您的regex似乎是正确的(它匹配任何不超过1空格或1点的字符串)，但是您的函数中的逻辑似乎是错误的。

What it's doing: anytime the value changes, take the value and replace anything that matches that regex with an empty string, so any time you write a character its replaced (because it matches the regex).

它的作用是:当值发生变化时，取值并用空字符串替换与regex匹配的任何内容，这样每当您编写它所替换的字符时(因为它与regex匹配)。

I would go with one of this options:

我会选择其中一个选项:

a) show a message if the value doesn't match the regex

a)如果值与regex不匹配，则显示一条消息

b) change the regex to /.{2}| {2}/ and only replace the two dots or the two spaces, as Scath says in another answer

b)将regex更改为/。{2}|{2}/只替换两个点或两个空格，正如Scath在另一个答案中所说

c) maybe just using the input pattern attribute with your original regex is enough: https://www.w3schools.com/TAGS/att_input_pattern.asp

c)可能仅仅使用输入模式属性和原始regex就足够了:https://www.w3schools.com/TAGS/att_input_pattern.asp

Hope this helps!

希望这可以帮助!

#3

With this solution it deletes only the second space or second dot and the first ones will still remain:

有了这个解决方案，它只删除第二个空间或第二个点，第一个点仍然保留:

function test(input){
  var regex=/\.(?=\.)|\s(?=\s)/;
  input.value = input.value.replace(regex, "");
}

<input id="txt_NomCandidato" onkeyup="test(this);" type="text" class="form-control" name="txt_Nom">

#4

To achieve expected result, use below option of slice

为了达到预期的效果，使用下面的切片选项

input.value.slice(-2) will return last two entered characters and if it is ".." or " "(double spaces) replace it with ''

slice(-2)将返回最后两个输入字符，如果是“..”或“”(双空格)，则将其替换为“”

function test(input){
  if(input.value.slice(-2)=='..' || input.value.slice(-2)=='  '){
         input.value = input.value.replace(input.value.slice(-2), "");
     }
}

<input id="txt_NomCandidato" onkeyup="test(this);" type="text" class="form-control" name="txt_Nom">

code sample - https://codepen.io/nagasai/pen/VXNOej

代码示例——https://codepen.io/nagasai/pen/VXNOej

Your regex clears any characters starts with [A-Z] or [a-z] due to expression ^[A-Za-z]

你的正则表达式清除任何字符开始[a - z]或[a - z]由于表达^[A-Za-z]

#5

This regex will not allow them to enter two periods or two spaces, when they enter the second of either it will clear.

这个regex将不允许它们进入两个周期或两个空间，当它们进入第二个周期或两个空间时，它们将被清除。

function test(input){
  var regex=/\.{2}| {2}/;
  input.value = input.value.replace(regex, "").replace(/\d+|/g, '').replace(/\s+/g, ' ').replace(/[^\w]/, '');
}

<input id="txt_NomCandidato" onkeyup="test(this);" type="text" class="form-control" name="txt_Nom">

#6

That is because you match [A-Za-z]+ which will match one or more characters and everything after that is optional.

这是因为您匹配[A-Za-z]+，它将匹配一个或多个字符，之后的所有内容都是可选的。

Your regex would match.

你的正则表达式匹配。

• [A-Za-z]+ Match one or more characters
• [A-Za-z]+匹配一个或多个字符。
• \.{0,1} Match optional dot (0 or 1 times)
• \。{0,1}匹配可选点(0或1次)
• \s{0,1} match optional whitespace character (0 or 1 times)
• \s{0,1}匹配可选空格字符(0或1次)

Which will match a and then you will do the replace.

它将匹配a，然后进行替换。

To make something optional you could also use a question mark ?

要做一些可选的东西，你也可以用问号?

To only allow characters, a single whitespace or a single dot you could replace all that does not match those criteria:

为了只允许字符、一个空格或一个点，您可以替换所有不符合这些条件的字符:

([. ])(?=\1)|[^a-zA-Z. ]

((。)(? = \ 1)|(^ a-zA-Z。]

function test(input) {
  var regex = /([. ])(?=\1)|[^a-zA-Z. ]/;
  input.value = input.value.replace(regex, "");
}

<form id="" name="">
  <input id="txt_NomCandidato" onkeyup="test(this);" type="text" class="form-control" name="txt_Nom">
</form>

To match a dot followed by a dot or a white space followed by a white space you could capture a dot or a white space in a group and it will match if it is followed by what is captured in the group using a positive lookahead.

要匹配一个点后面跟着一个点或一个空格后面跟着一个空格，你可以在一个组中捕获一个点或一个空格，如果它后面跟着一个点或一个空格，那么它就会匹配，如果它后面跟着一个用正向前视捕获的组。

([. ])(?=\1)

((。)(? = \ 1)