NameAbbreviator.java

public class NameAbbreviator {

    /**
     * Returns an abbreviated version of a full name.
     * All names except the last are abbreviated to a single letter followed by a period.
     *
     * e.g. "Thomas James Turner" -> "T.J. Turner"
     *
     * @param fullName the full name to abbreviate
     * @return the abbreviated name
     */
    public static String abbreviate(String fullName) {
        String[] names = fullName.split(" ");
        String result = "";

        for(int i = 0; i < names.length ; i++) {
            if (i == names.length-1) {
                if (i > 0) {
                    result += " ";
                }
                result += names[i];
            } else {
                result += names[i].charAt(0) + ".";
            }
        }

        return result;
    }

    // -------------------------------------------------------------------------
    // Test runner
    // -------------------------------------------------------------------------

    public static void main(String[] args) {
        int passed = 0, failed = 0;

        Object[][] tests = {
            // { input, expected }
            { "Thomas James Turner",   "T.J. Turner"  },  // basic 3-part name
            { "Tom Turner",            "T. Turner"    },  // 2-part name
            { "Turner",                "Turner"       },  // single name (no abbreviation)
            { "A B C D Turner",        "A.B.C.D. Turner" }, // many middle names
            { "thomas james turner",   "t.j. turner"  },  // lowercase preserved
            { "THOMAS JAMES TURNER",   "T.J. TURNER"  },  // uppercase preserved
        };

        for (Object[] test : tests) {
            String input    = (String) test[0];
            String expected = (String) test[1];
            String actual   = abbreviate(input);
            boolean ok      = expected.equals(actual);
            System.out.printf("  %-35s -> %-20s %s%n",
                "\"" + input + "\"",
                "\"" + actual + "\"",
                ok ? "PASS" : "FAIL (expected \"" + expected + "\")");
            if (ok) passed++; else failed++;
        }

        System.out.printf("%nResults: %d passed, %d failed%n", passed, failed);
    }
}