Question

用正则表达式在java怎么去匹配注释 //的单行注释 /*单行注释*/ /* *多行注释 */

Answer 1

先说结果：
我是测试出来了正则表达式，但是是针对三种注释，写了三种正则。
没有实现单一的正则表达式，支持所有的注释类型的。
代码你可以参考参考：

//单行注释
String commentsStr = "//this is single line comments";
Pattern singleLineCommentP = Pattern.compile("^//.*?$");
Matcher foundSingleLineComment = singleLineCommentP.matcher(commentsStr);
boolean foundSingle = foundSingleLineComment.matches();
System.out.println(foundSingleLineComment);
System.out.println(foundSingle);

/*单行注释*/
String doubleStarCommentStr = "/* this is double star comments */";
Pattern doubleStarCommentP = Pattern.compile("^/\\*.*?\\*/$");
Matcher foundDoubleStarComment = doubleStarCommentP.matcher(doubleStarCommentStr);
boolean foundDouble = foundSingleLineComment.matches();
System.out.println(foundDoubleStarComment);
System.out.println(foundDouble);

/*
*多行注释
*/

String multiLineComments = "/* \n" +
"* this is \n" +
"* multi line comment \n" +
"*/";
Pattern multiLineCommentP = Pattern.compile("^/\\*.*\\*/$", Pattern.DOTALL);
Matcher foundMultiLineComment = multiLineCommentP.matcher(multiLineComments);
boolean foundMulti = foundMultiLineComment.matches();
System.out.println(foundMultiLineComment);
System.out.println(foundMulti);

感兴趣的话，可以去看看我总结的：
crifan 正则表达式学习心得

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Answer 2

\/\*[\w\W]*?\*\/|\/\/.*

Answer 3

^//.*$|^/\*.*\*/$|^/\*\*.*$|^\*.*$|.*\*/$

追问

不能用呀

追答

可以用啊