如何检查字符串是否包含法语字母？

Question

在Java中，如何检查字符串是否包含法语字母？

Answer 1

public static boolean containsFrench(String s) {
    Pattern frenchPattern = Pattern.compile("(?i)[çèéêîôœû]");
    return frenchPattern.matcher(s).find();
}

Answer 2

Since the notion of a "french letter" is poorly defined, the simplest way to solve this would be to create an array containing all letters that you think qualify, and then just test each character in the string to see if it is in the array:

(I'm not going to write the code for you because this is something that anyone who has done a Java course or tutorial should be able to write in five minutes. And if you can't do it in 5 minutes, then you need to practice by doing it yourself.)

There are more elegant and/or more efficient ways to do this. But simple is good for a beginner.

Answer 3

Quick solution - you might want to check that the list is exhaustive (for example, I have not included accented large caps or the ÿ which is not very common) but the concept should work:

public static void main(String[] args) {
    Set<Character> frenchLetters = new HashSet<> (Arrays.asList('â', 'à', 'ç', 'é', 'ê', 'ë', 'è', 'ï', 'î', 'ô', 'û', 'ù'));
    String s = "abcdà";
    for (char c : s.toCharArray()) {
        if (frenchLetters.contains(c)) {
            System.out.println("Found a French letter: " + c);
        }
    }
}

Answer 4

Try:

public boolean hasFrenchCharacter(String input) {
    if (input.contains("ù") == true) return true;
    if (input.contains("û") == true) return true;
    if (input.contains("ü") == true) return true;
    if (input.contains("ÿ") == true) return true;
    if (input.contains("à") == true) return true;
    if (input.contains("â") == true) return true;
    if (input.contains("æ") == true) return true;
    if (input.contains("ç") == true) return true;
    if (input.contains("é") == true) return true;
    if (input.contains("è") == true) return true;
    if (input.contains("ê") == true) return true;
    if (input.contains("ë") == true) return true;
    if (input.contains("ï") == true) return true;
    if (input.contains("î") == true) return true;
    if (input.contains("ô") == true) return true;
    if (input.contains("œ") == true) return true;
    return false;
}

It will return true if it has a French character, false otherwise.

Really this is not the way I would do it, I would do it this way:

public boolean hasFrenchCharacter(String input) {
    return input.contains("ù") ||
           input.contains("û") ||
           input.contains("ü");
    //and so on...
}