Question

I need to find special escape java chars (\n, \t, \b, etc.) in a grooup of strings and then print what strings contain which special chars. So, when printing I would like to change the char value itself by a string “\n” for ‘\n’, “\t” for ‘\t’ and so on. I did with a switch statement for all this type of characters. I wonder if there is a solution that doesn’t involve checking for each one of the???

Answer 1

I didn’t find a library for that, but on the other hand, my quick implementation doesn’t look too terrible – I’d prefer this even over a RegExp 😉

public String unescape(String s) {
    StringBuilder result = new StringBuilder();
    for (char c : s.toCharArray()) {
        result.append(toLiteral(c));
    }
    return result.toString();
}

private String toLiteral(char c) {
    switch (c) {
    case '\n':
        return "\\n";
    case '\t':
        return "\\t";
    case '\r':
        return "\\r";
    case '\f':
        return "\\f";
    case '\b':
        return "\\b";
    case '\'':
        return "\\\'";
    case '\"':
        return "\\\"";
    case '\\':
        return "\\\\";
    default:
        return c;
    }
}

According to my compiler, theses are all escape sequences that are allowed for Strings.