Smalltalk and Object Orientation: an Introduction - Free

aCharacter isAlphabetic.
aCharacter isDigit.
aCharacter isLetter.
aCharacter isLowercase.
aCharacter isVowel.
It also provides some useful conversion methods, including:
aCharacter asUppercase.
aCharacter asLowercase.
aCharacter asInteger.
The first two messages would convert the contents of aCharacter either to an uppercase character or
a lowercase character while the third message would return the ASCII code a letter or number.
Just like the classes Date and Time, the Character class provides some useful class side
protocol. The methods provided on the class side provide access to non -alphanumeric characters. These
can be extremely useful w hen processing text (as was illustrated in the example presented earlier in the
book). The facilities available allow you to obtain the character for carriage return, backspace, space,
new page and tab (amongst others). For example:
newlineChar := Character cr.
spaceChar := Character space.
tabChar := Character tab.
14.6 Further reading
The Object Reference manual supplied with your Smalltalk system will provide a detailed description
of all the classes described in this chapter. For a detailed description of t he Number hierarchy see
[Hopkins and Horan 1995].
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