Character

"Hi, Amigo! It's me again. I'd like to tell you about another fairly simple wrapper class. Today we'll be talking about Character, the wrapper for char."

"This class is also quite simple."

class Character
{
 private final char value;

 Character(char value)
 {
  this.value = value;
 }

 public char charValue()
 {
  return value;
 }

 static final Character cache[] = new Character[127 + 1];

 public static Character valueOf(char c)
 {
  if (c <= 127)
   return cache[(int)c];

  return new Character(c);
 }

 public int hashCode()
 {
  return (int)value;
 }

 public boolean equals(Object obj)
 {
  if (obj instanceof Character)
  {
   return value == ((Character)obj).charValue();
  }
  return false;
 }
}

"It has the following:"

1) A constructor that takes the internal value and a charValue method that returns it.

2) A valueOf method that returns Character objects, but caches objects with values from 0 to 127. Just like Integer, Short, and Byte.

3) hashCode() and equals methods — again, there's nothing surprising here.

"And it has lots of other useful methods (not shown above). I'll list a few for you here:"

boolean isDefined(char)

boolean isDigit(char)

boolean isISOControl(char)

boolean isLetter(char)

boolean isJavaLetterOrDigit()

boolean isLowerCase(char)

boolean isUpperCase(char)

boolean isSpaceChar(char)

boolean isTitleCase(char)

"Thank you, Kim. I think some of these methods will be useful for me."