正则表达式匹配除“DC”之外的所有标点符号

Question

我正在尝试编写一个查找所有标点符号 [.!?] 的正则表达式，以便将下一个单词大写，但是如果句点是字符串 'DC' 的一部分，它应该被忽略，到目前为止我有第一部分工作，但不确定如何忽略“DC”

const punctuationCaps = /(^|[.!?]\\s+)([az])/g;

Answer 1

You can match the DC part and use an alternation using the 2 capturing groups that you already have.

In the replacement check for one of the groups. If it is present, concatenate them making group 2 toUpperCase(), else return the match keeping DC in the string.

 const regex = /D\\.C\\.|(^|[.!?]\\s+)([az])/g; let s = "this it DC test. and? another test! it is."; s = s.replace(regex, (m, g1, g2) => g2 ? g1 + g2.toUpperCase() : m); console.log(s);

Answer 2

Use a negative lookahead:

 var str = 'is DC a capital? i don\\'t know about XY stuff.'; var result = str.replace(/(^|[.!?](?<![AZ]\\.[AZ]\\.)\\s+)([az])/g, (m, c1, c2) => { return c1 + c2.toUpperCase(); }); console.log('in: '+str); console.log('out: '+result);

Console output:

in:  is D.C. a capital? i don't know about X.Y. stuff.
out: Is D.C. a capital? I don't know about X.Y. stuff.

Explanation:

• (^|[.!?]) - expect start of string, or a punctuation char
• (?<![AZ]\\.[AZ]\\.) - negative lookahead: but not a sequence of upper char and dot, repeated twice
• \\s+ - expect one or more whitespace chars
• all of the above is captured because of the parenthesis
• ([az]) - expect a lower case char, in parenthesis for second capture group