需要一个正则表达式，它不应该只允许字符串中有空格，它可以允许字符中有空格。
例如：空格+字符+空格是允许的，而as only空格是不允许的
/S/足以匹配非空字符串。
试试这个：
/^s+$
根据您的条件，任何与上述表达式匹配的字符串都是无效的。
也许在对字符串使用trim（）之后测试它的空性更容易、更快。
如果你只是在寻找一个积极的匹配：
/S/
如果要捕获：
/(.*S.*)/
编辑：
实际上，如果您指的是文字空间：
/[ ]/
您只需强制非空格字符至少出现一次：
s*s+s*
Recently I discovered two amazing regular expression features: ?: and ?!. I was curious of other neat regex features. So maybe you would like to share some tricky regular expressions.
I need to remove image tags from text, so both versions of the tag: <img src="" ... ></img> <img src="" ... />
How do I, using preg_replace, replace more than one underscore with just one underscore?
I was trying to write a regexp to replace all occurrences of with unless the is already preceeded immediately by a . I m doing this in Ruby 1.8.6 which doesn t support look behind in ...
Specifically, I have an array of strings called val, and want to replace all instances of "%{n}%" in the input with val[n]. More generally, I want the replace value to be a function of the match ...
I have the following log entry that I am processing in PowerShell I m trying to extract all the activity names and durations using the -match operator but I am only getting one match group back. I m ...
I m building a lexical analysis engine in c#. For the most part it is done and works quite well. One of the features of my lexer is that it allows any user to input their own regular expressions. This ...
I need a regex for four-digit numbers separated by comma ("default" can also be a value). Examples: 6755 3452,8767,9865,8766,3454 7678,9876 1234,9867,6876,9865 default Note: "default" ...