Removing certain characters from a string

Question

I am thinking about using String.replaceAll() to remove certain characters in my string. It is unclear which characters are going to be removed (i.e. which char

Answer 1

I think you are looking for a code like this to solve your problem without any looping:

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class StripChars {
    public static void main(String[] args) {
    // prints: Just to clarify I will have strings of varying lengths   
    System.out.println(
     replace("Just to clarify, I will have strings of varying lengths.",
               ",."));

    // prints: Solution to my problem on Stackoverflow will cost me 0
    System.out.println(
     replace("Solution to my problem on stackoverflow will cost me $0.", 
               ".$"));      
    }

    static String replace(String line, String charsToBeReplaced) {
        Pattern p = Pattern.compile("(.{1})");
        Matcher m = p.matcher(charsToBeReplaced);
        return line.replaceAll(m.replaceAll("\\\\$1\\|"), "");
    }
}

To take care of special regex characters (meta-characters) in input replace method is first putting \ (backslash) before each character and a | (pipe) after each character in your input. So an input of ",." will become "\\,|\\.|"

Once that is done then replacement is pretty simple: for every matching char replace it by a blank.

Not used in this solution but here is the pattern to detect presence of ANY special regex character in Java:

Pattern metachars = Pattern.compile(
   "^.*?(\\(|\\[|\\{|\\^|\\-|\\$|\\||\\]|\\}|\\)|\\?|\\*|\\+|\\.).*?$");