Java: Exercise - Capitalize Words

Problem

Write a method which which returns a string first letter in every word capitalized and every other letter in lowercase. Assume the first letter is any letter preceded by a non-alphabetic. This is slightly more difficult than Exercise - Count Words, but uses the same basic algorithm.

Signature

    public static String capitalizeWords(String s)

Note: This is declared static because it is doesn't depend on any instance variables from the class it would be defined in. It's declared public only because it might be generally useful.

Example

Call	Returns	Comments
capitalizeWords("hello world")	"Hello World"	Each word capitalized.
capitalizeWords("HELLO WORLD")	"Hello World"	Each word capitalized, remainder lowercase.
capitalizeWords("Hello World")	"Hello World"	Result happens to be the same.
capitalizeWords("Don't worry?")	"Don'T Worry?	The quote starts new word. See Extensions section.
capitalizeWords("Easy as 123")	"Easy As 123"	Only alphabetics are affected.

Hints

One way to solve this is to go down the string one character at a time. Use a boolean variable to indicate whether you're in a word or not. When the variable indicates that you're in a word, change alphabetics to lowercase (use Character.toLowerCase()). You can test for alphabetic characters with Character.isLetter(). If an alphabetic character is encountered when you're outside a word, it must be the first letter so it should be changed to uppercase with Character.toUpperCase() and switch the state of the boolean variable.

Extensions

A better definition of "word" would make this better. For example, non-alphabetics between words should only count if they include at least one blank so that contractions like "don't" aren't counted as two words.

Assumptions

Write only the method. You can easily change the Example - Generic Calc program to use this method.