Java字符串替换所有正则表达式

Question

Hi I want to remove certain words from a long string, there problem is that some words end with "s" and some start with a capital, basically I want to turn:

"Hello cat Cats cats Dog dogs dog fox foxs Foxs"

into:

"Hello"

at the moment I have this code but I want to improve on it, thanks in advance:

                    .replace("foxs", "")
                    .replace("Fox", "")
                    .replace("Dogs", "")
                    .replace("Cats", "")
                    .replace("dog", "")
                    .replace("cat", "")

Answer 1

Try this:

String input = "Hello cat Cats cats Dog dogs dog fox foxs Foxs";
input = input.replaceAll("(?i)\\s*(?:fox|dog|cat)s?", "");

Demo

Answer 2

Maybe you can try to match everything except the word Hello . Something like:

string.replaceAll("(?!Hello)\\b\\S+", "");

You can test it in this link .

The idea is to perform a negative lookahead for Hello word, and get any other word present.

Answer 3

You can generate patterns that match all combinations for a word. Ie for dog you need the pattern [Dd]ogs? :

• [Dd] is a character class that matches both cases
• s? matches zero or one s
• the rest of the word will be case sensitive. Ie dOGS will not be a match.

This is how you can put it together:

public static void main(String[] args) {
    // it's easy to add any other word
    String original = "Hello cat Cats cats Dog dogs dog fox foxs Foxs";
    String[] words = {"fox", "dog", "cat"};
    String tmp = original;
    for (String word : words) {
        String firstChar = word.substring(0, 1);
        String firstCharClass = "[" + firstChar.toUpperCase() + firstChar.toLowerCase() + "]";
        String patternSrc = firstCharClass + word.substring(1) + "s?"; // [Ww]ords?
        tmp = tmp.replaceAll(patternSrc, "");
    }
    tmp = tmp.trim(); // to remove unnecessary spaces 
    System.out.println(tmp);
}

Answer 4

So you could pre-compile a list of the words you want and make it case insensitive something like:

    String str = "Hello cat Cats cats Dog dogs dog fox foxs Foxs";
    Pattern p = Pattern.compile("fox[s]?|dog[s]?|cat[s]?", Pattern.CASE_INSENSITIVE);
    Matcher m = p.matcher(str);
    String result = m.replaceAll("");
    System.out.println(result);

[s]? handles if there is a plural form, where the ? character will match 0 or 1