Java String Special character replacement

Question

I have string which contains alpahanumeric and special character. I need to replace each and every special char with some string.

For eg,

Input string = "ja*va st&ri%n@&" Expected o/p = "jaasteriskvaspacestandripercentagenatand"

• = "asterisk" & = "and" % = "percentage" @ = "at"

thanks,

Answer 1

Unless you're absolutely desperate for performance, I'd use a very simple approach:

String result = input.replace("*", "asterisk")
                     .replace("%", "percentage")
                     .replace("@", "at"); // Add more to taste :)

(Note that there's a big difference between replace and replaceAll - the latter takes a regular expression. It's easy to get the wrong one and see radically different effects!)

An alternative would be something like:

public static String replaceSpecial(String input)
{
    // Output will be at least as long as input
    StringBuilder builder = new StringBuilder(input.length());

    for (int i = 0; i < input.length(); i++)
    {
        char c = input.charAt(i);
        switch (c)
        {
            case '*': builder.append("asterisk"); break;
            case '%': builder.append("percentage"); break;
            case '@': builder.append("at"); break;
            default: builder.append(c); break;
        }
    }
    return builder.toString();

Answer 2

Take a look at the following java.lang.String methods:

• replace()
• replaceAll()