Java Regex如何查找字符串是否包含字符，但顺序不是问题

Question

I have String like this "abcdefgh"

I want to check the string contains the following characters [fcb]

Condition is : The string must contain all characters in any order .

How to write a regex for this one.

I tried following regexes :

.*[fcb].* ---> In this case it not check all characters. If any one character matchs it will return true

Answer 1

Don't use regex. Just use String.contains to test for each of the characters in turn:

in.contains("f") && in.contains("c") && in.contains("b")

Answer 2

You could get the char arry and sort it. Afterwards you could check if it contains .*b.*c.*f.* .

public static boolean contains(String input) {
    char[] inputChars = input.toCharArray();
    Arrays.sort(inputChars);
    String bufferInput = String.valueOf(inputChars);
    // Since it is sorted this will check if it simply contains `b,c and f`.
    return bufferInput.matches(".*b.*c.*f.*");
}

public static void main(String[] args) {
    System.out.println(contains("abcdefgh"));
    System.out.println(contains("abdefgh"));
}

output:

true 
false

Answer 3

this will check if all the letters are present in the string.

public class Example {

public static void main(String args[]) {

    String stringA = "abcdefgh";

    String opPattern = "(?=[^ ]*f)(?=[^ ]*c)(?=[^ ]*b)[^ ]+";
    Pattern opPatternRegex = Pattern.compile(opPattern);

    Matcher matcher = opPatternRegex.matcher(stringA);

    System.out.println(matcher.find());

}
}

Answer 4

你可以使用positive lookahead

(?=.*b)(?=.*c)(?=.*f)

Answer 5

不是很有效但很容易理解：

if (s.matches(".*b.*") && s.matches(".*c.*") && s.matches(".*f.*"))