# Converting strings between uppercase and lowercase

As the following example shows, the `toLowerCase()` method and the
`toUpperCase()` method convert alphabetical characters in the string to
lowercase and uppercase, respectively:

    var str:String = "Dr. Bob Roberts, #9."
    trace(str.toLowerCase()); // dr. bob roberts, #9.
    trace(str.toUpperCase()); // DR. BOB ROBERTS, #9.

After these methods are executed, the source string remains unchanged. To
transform the source string, use the following code:

    str = str.toUpperCase();

These methods work with extended characters, not simply a–z and A–Z:

    var str:String = "José Barça";
    trace(str.toUpperCase(), str.toLowerCase()); // JOSÉ BARÇA josé barça
