特定的正则表达式模式

Question

I wish to take a string input from the user and extract words or numbers like so:

String problem = "I'm lo#o@king t%o ext!r$act a^ll 6 su*bs(tr]i{ngs.";

String[] solve = {"I'm", "looking", "to", "extract", "all", "6", "substrings"};

Basically, I want to extract numbers and words with complete disregard to punctuation except apostrophes. I know how to get words and strings but I can't seem to figure out this tricky part.

Answer 1

You could do like the below.

String s = "I'm lo#o@king t%o ext!r$act a^ll 6 su*bs(tr]i{ngs.";
String parts[] = s.replaceAll("[^\\s\\w']|(?<!\\b)'|'(?!\\b)", "").split("\\s+");
System.out.println(Arrays.toString(parts));

Output:

[I'm, looking, to, extract, all, 6, substrings]

Explanation:

• [^\\\\s\\\\w'] matches any character but not of space or single quote or word character.

• (?<!\\\\b)'(?!\\\\b) matches the ' symbol only if it's not preceded and not followed by a word character.

• replaceAll function replaces all the matched characters with an empty string.

• Finally we do splitting on the resultant string according to one or more space characters.