正则表达式：否定集中只有一个字符实例
Regex: only single instance of character in negated set
有什么方法可以将否定集中的字符限制为单个实例吗？
我在做什么：
[^0-9\.]
这不会匹配数字和小数，但是有什么方法可以限制为单个小数吗？
所以它不会匹配：
84.34356
.3948
但会匹配：
86..3232
^
84.54.23.
^ ^
这边
val.replace(/[^0-9\.]/g, '')
将替换匹配的字符
使用 split、shift 和 join：
var s = '84.54.23.'
var arr = s.split(/\./).filter(Boolean)
if (arr.length > 1)
s = arr.shift() + '.' + arr.join('')
//=> s="84.5423"
s = '86..3232'
arr = s.split(/\./).filter(Boolean)
if (arr.length > 1)
s = arr.shift() + '.' + arr.join('')
//=> s="86.3232"
s = '84.34356'
arr = s.split(/\./).filter(Boolean)
if (arr.length > 1)
s = arr.shift() + '.' + arr.join('')
//=> s="84.34356"
s = '.3948'
arr = s.split(/\./).filter(Boolean)
if (arr.length > 1)
s = arr.shift() + '.' + arr.join('')
//=> s=".3948"
描述
^([0-9]+[.](?=[.]+)|[0-9]+[.][0-9]+|[.][0-9]+)|(?<=[0-9])[.]|[.](?=[0-9]|$)
替换为： </code></p>
<p><WBIMG:3996444-1.png></p>
<p>此正则表达式将执行以下操作：</p>
<ul>
<li>替换数字中或周围不需要的小数点</li>
<li>在常规文本周围保留小数点</li>
</ul>
<h1>例子</h1>
<p><strong>现场演示</strong></p>
<p><a href="https://regex101.com/r/pF4aS3/2" rel="nofollow">https://regex101.com/r/pF4aS3/2</a></p>
<p><strong>示例文本</strong></p>
<pre><code>84.34356
.3948
but will match.:
86..3232
84.54.23.
替换后
84.34356
.3948
but will match.:
86.3232
84.5423
说明
NODE EXPLANATION
----------------------------------------------------------------------
^ the beginning of the string
----------------------------------------------------------------------
( group and capture to :
----------------------------------------------------------------------
[0-9]+ any character of: '0' to '9' (1 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
(?= look ahead to see if there is:
----------------------------------------------------------------------
[.]+ any character of: '.' (1 or more times
(matching the most amount possible))
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[0-9]+ any character of: '0' to '9' (1 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
[0-9]+ any character of: '0' to '9' (1 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
[0-9]+ any character of: '0' to '9' (1 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
) end of
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
(?<= look behind to see if there is:
----------------------------------------------------------------------
[0-9] any character of: '0' to '9'
----------------------------------------------------------------------
) end of look-behind
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
(?= look ahead to see if there is:
----------------------------------------------------------------------
[0-9] any character of: '0' to '9'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
$ before an optional \n, and the end of
the string
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
有什么方法可以将否定集中的字符限制为单个实例吗？
我在做什么： [^0-9\.]
这不会匹配数字和小数，但是有什么方法可以限制为单个小数吗？
所以它不会匹配：
84.34356
.3948
但会匹配：
86..3232
^
84.54.23.
^ ^
这边
val.replace(/[^0-9\.]/g, '')
将替换匹配的字符
使用 split、shift 和 join：
var s = '84.54.23.'
var arr = s.split(/\./).filter(Boolean)
if (arr.length > 1)
s = arr.shift() + '.' + arr.join('')
//=> s="84.5423"
s = '86..3232'
arr = s.split(/\./).filter(Boolean)
if (arr.length > 1)
s = arr.shift() + '.' + arr.join('')
//=> s="86.3232"
s = '84.34356'
arr = s.split(/\./).filter(Boolean)
if (arr.length > 1)
s = arr.shift() + '.' + arr.join('')
//=> s="84.34356"
s = '.3948'
arr = s.split(/\./).filter(Boolean)
if (arr.length > 1)
s = arr.shift() + '.' + arr.join('')
//=> s=".3948"
描述
^([0-9]+[.](?=[.]+)|[0-9]+[.][0-9]+|[.][0-9]+)|(?<=[0-9])[.]|[.](?=[0-9]|$)
替换为： </code></p>
<p><WBIMG:3996444-1.png></p>
<p>此正则表达式将执行以下操作：</p>
<ul>
<li>替换数字中或周围不需要的小数点</li>
<li>在常规文本周围保留小数点</li>
</ul>
<h1>例子</h1>
<p><strong>现场演示</strong></p>
<p><a href="https://regex101.com/r/pF4aS3/2" rel="nofollow">https://regex101.com/r/pF4aS3/2</a></p>
<p><strong>示例文本</strong></p>
<pre><code>84.34356
.3948
but will match.:
86..3232
84.54.23.
替换后
84.34356
.3948
but will match.:
86.3232
84.5423
说明
NODE EXPLANATION
----------------------------------------------------------------------
^ the beginning of the string
----------------------------------------------------------------------
( group and capture to :
----------------------------------------------------------------------
[0-9]+ any character of: '0' to '9' (1 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
(?= look ahead to see if there is:
----------------------------------------------------------------------
[.]+ any character of: '.' (1 or more times
(matching the most amount possible))
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[0-9]+ any character of: '0' to '9' (1 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
[0-9]+ any character of: '0' to '9' (1 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
[0-9]+ any character of: '0' to '9' (1 or more
times (matching the most amount
possible))
----------------------------------------------------------------------
) end of
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
(?<= look behind to see if there is:
----------------------------------------------------------------------
[0-9] any character of: '0' to '9'
----------------------------------------------------------------------
) end of look-behind
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
[.] any character of: '.'
----------------------------------------------------------------------
(?= look ahead to see if there is:
----------------------------------------------------------------------
[0-9] any character of: '0' to '9'
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
$ before an optional \n, and the end of
the string
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------