Numbers - Java - page 192

}
/* Implement a toy stack */
protected protected int int pop () {

return return stack [-- depth ];

}

}

Several of the public methods are required because I wanted it to be a subclass of Format ,
which is abstract. This accounts for some of the complexity, like having three different
format methods.

Note that the parseObject( ) method is also required, but we don't actually implement
parsing in this version. This is left as an exercise for the reader.

See Also

Java I/O (O'Reilly) includes an entire chapter on NumberFormat and develops the subclass
ExponentialNumberFormat .

The online source for this topic has ScaledNumberFormat , which prints numbers with a
maximum of four digits and a computerish scale factor (B for bytes, K for kilo-, M for mega-
, and so on).

Formatting with Correct Plurals

Problem

You're printing something like "We used " + n + " items" , but in English, “We used 1
items” is ungrammatical. You want “We used 1 item.”

Solution

Use a ChoiceFormat or a conditional statement.

Use Java's ternary operator ( cond ? trueval : falseval ) in a string concatenation. Both
zero and plurals get an “s” appended to the noun in English (“no books, one book, two
books”), so we test for n==1 :