javascript 正则表达式仅匹配字符或空格或两个单词之间的一个点，不允许使用双空格
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Regular expression to match only character or space or one dot between two words, no double space allowed
提问by user3291547
I need help with regular expression.I need a expression in JavaScript which allows only character or space or one dot between two words, no double space allowed.
我需要正则表达式方面的帮助。我需要一个 JavaScript 表达式，它只允许字符或空格或两个单词之间的一个点，不允许使用双空格。
I am using this
我正在使用这个
var regexp = /^([a-zA-Z]+\s)*[a-zA-Z]+$/;
but it's not working.
但它不起作用。
Example
例子
1. hello space .hello - not allowed
2. space hello space - not allowed
采纳答案by Subdigger
try this:
试试这个：
^(\s?\.?[a-zA-Z]+)+$
EDIT1
编辑1
/^(\s{0,1}\.{0,1}[a-zA-Z]+)+$/.test('space ..hello space')
false
/^(\s{0,1}\.{0,1}[a-zA-Z]+)+$/.test('space .hello space')
true
v2:
v2：
/^(\s?\.?[a-zA-Z]+)+$/.test('space .hello space')
true
/^(\s?\.?[a-zA-Z]+)+$/.test('space ..hello space')
false
v3: if you need some thisn like one space or dot between
v3：如果你需要一些 this 那么像一个空格或点之间
/^([\s\.]?[a-zA-Z]+)+$/.test('space hello space')
true
/^([\s\.]?[a-zA-Z]+)+$/.test('space.hello space')
true
/^([\s\.]?[a-zA-Z]+)+$/.test('space .hello space')
false
v4:
v4：
/^([ \.]?[a-zA-Z]+)+$/.test('space hello space')
true
/^([ \.]?[a-zA-Z]+)+$/.test('space.hello space')
true
/^([ \.]?[a-zA-Z]+)+$/.test('space .hello space')
false
/^([ ]?\.?[a-zA-Z]+)+$/.test('space .hello space')
true
EDIT2Explanation:
EDIT2解释：
may be problem in \s = [\r\n\t\f ]
so if only space allowed - \s?can be replaced with [ ]?
\s = [\r\n\t\f ] 中可能有问题，所以如果只允许空格 -\s?可以替换为[ ]?
回答by gwcoffey
This regular expression will match multiple spaces or dots between words and spaces before the first word or after the last word. This is the opposite of what you want, but you can always invert it (!foo.match(...)):
此正则表达式将匹配单词之间的多个空格或点以及第一个单词之前或最后一个单词之后的空格。这与您想要的相反，但您始终可以反转它 ( !foo.match(...))：
/\b[\. ]{2,}\b|^ | $/
In regex101.com: http://regex101.com/r/fT0pF2
在regex101.com：http://regex101.com/r/fT0pF2
And in plainer english:
用更简单的英语：
\b => a word boundary
[\. ] => a dot or a space
{2,} => 2 or more of the preceding
\b => another word boundary
| => OR
^{space} => space after string start
| => OR
{space}$ => space before string end
This will match:
这将匹配：
"this that" // <= has two spaces
"this. that" // <= has dot space
" this that" // <= has space before first word
"this that " // <= has space after last word
But it will not match:
但它不会匹配：
"this.that and the other thing"
回答by j3ny4
How about that?
那个怎么样？
^\s*([a-zA-Z]+\s?\.?[a-zA-Z]+)+$
This allows:
这允许：
- Multiple leading spaces.
- Space as a delimiter.
- Dot in the second and any consecutive word.
- 多个前导空格。
- 空格作为分隔符。
- 点在第二个和任何连续的单词中。
回答by user2303197
Try this (only a single whitespace or a period is allowed between the words):
试试这个（单词之间只允许有一个空格或句号）：
> /\w+[\s\.]\w+/.test('foo bar')
true
> /\w+[\s\.]\w+/.test('foo.bar')
true
> /\w+[\s\.]\w+/.test('foo..bar')
false
> /\w+[\s\.]\w+/.test('foo .bar')
false
