RemoveCapitals.java

Download
1/* 2 * RemoveCapitals.java3 * 4 * Computer Science S-225 */6 7/**8 * Removing capital (upper case) letters from a string9 */10public class RemoveCapitals {11 12    /*13     * removeCapitals("HeLLo") calls removeCapitals("eLLo")14     *   removeCapitals("eLLo") calls removeCapitals("LLo")15     *     removeCapitals("LLo") calls removeCapitals("Lo")16     *       removeCapitals("Lo") calls removeCapitals("o")17     *         removeCapitals("o") calls removeCapitals("")18     *           removeCapitals("") returns ""19     *         removeCapitals("o") returns "o" + "" -> "o"20     *       removeCapitals("Lo") returns "o"21     *     removeCapitals("LLo") returns "o"22     *   removeCapitals("eLLo") returns "eo"23     * removeCapitals("HeLLo") returns "eo"24     */25    public static String removeCapitals(String str) {26        if (str.equals("")) {27            return str;28        }29 30        String rest = removeCapitals(str.substring(1));31        char first = str.charAt(0);32 33        if (Character.isUpperCase(first)) {34            return rest;35        } else {36            return first + rest;37        }38    }39 40    public static void main(String[] args) {41        String input = "HeLLo";42        if (args.length > 0) {43            input = args[0];44        }45 46        System.out.println(removeCapitals(input));47    }48}