I'm constructing a regular expression that uses strings input by the user but the strings might contain special characters such as . \ or * and I want those to be treated as literals and not interpreted by their special meanings in the regex. I've tried this:
我正在构造一个正则表达式，它使用用户输入的字符串，但是字符串可能包含一些特殊的字符，比如。\或*，我希望将它们视为文字，而不是通过它们在regex中的特殊含义进行解释。我已经试过这个:
NSString *word = [input stringByReplacingOccurrencesOfRegex:@"(\\P{L})" withString:@"\\$1"];
but the non letter characters are converted to '$1' instead of being prefixed with a backslash. I've tried one and three backslashes in the second term but those give me an 'Unknown escape sequence' warning in XCode. How can I print a backslash without RegexKitLite thinking that I'm escaping the dollar sign?
但是非字母字符被转换为$1，而不是以反斜杠作为前缀。在第二学期中，我尝试过三次反斜杠，但在XCode中，这些都给了我一个“未知的转义序列”警告。我怎么能在没有RegexKitLite的情况下打印反斜杠呢?
1 个解决方案
#1
7
Write the expression as you normally would and then replace each single backslash with two. Thus
像往常一样编写表达式，然后用两个反斜杠替换每个反斜杠。因此
\.
becomes
就变成了
\\.
and
和
\\
becomes
就变成了
\\\\
#1
7
Write the expression as you normally would and then replace each single backslash with two. Thus
像往常一样编写表达式，然后用两个反斜杠替换每个反斜杠。因此
\.
becomes
就变成了
\\.
and
和
\\
becomes
就变成了
\\\\