| Java 1.1 | cloneable serializable |
This
class is a subclass of Format that converts a
number to a String in a way reminiscent of a
switch statement or an enumerated type. Each
ChoiceFormat object has an array of doubles known
as its limits and an array of strings known as
its formats . When the format(
) method is called to format a number x,
the ChoiceFormat finds an index
i such that:limits[i] <= x < limits[i+1]If x is less than the first element of the array,
the first element is used, and if it is greater than the last, the
last element is used. Once the index i has been
determined, it is used as the index into the array of strings, and
the indexed string is returned as the result of the format(
) method.A ChoiceFormat object may also be created by
encoding its limits and formats into a single string known as its
pattern . A typical pattern looks like the one
below, used to return the singular or plural form of a word based on
the numeric value passed to the format( ) method:ChoiceFormat cf = new ChoiceFormat("0#errors|1#error|2#errors");A ChoiceFormat object created in this way returns
the string "errors" when it formats
the number 0 or any number greater than or equal to 2. It returns
"error" when it formats the number
1. In the syntax shown here, note the pound sign
(#) used to separate the limit number from the
string that corresponds to that case and the vertical bar
(|) used to separate the
individual cases. You can use the
applyPattern( ) method to change the pattern used
by a ChoiceFormat object; use toPattern(
) to query the pattern it uses.
Figure 15-4. java.text.ChoiceFormat
 public class ChoiceFormat extends NumberFormat {
// Public Constructors
public ChoiceFormat (String newPattern );
public ChoiceFormat (double[ ] limits , String[ ] formats );
// Public Class Methods
public static final double nextDouble (double d );
public static double nextDouble (double d , boolean positive );
public static final double previousDouble (double d );
// Public Instance Methods
public void applyPattern (String newPattern );
public Object[ ] getFormats ( );
public double[ ] getLimits ( );
public void setChoices (double[ ] limits , String[ ] formats );
public String toPattern ( );
// Public Methods Overriding NumberFormat
public Object clone ( );
public boolean equals (Object obj );
public StringBuffer format (long number , StringBuffer toAppendTo ,
FieldPosition status );
public StringBuffer format (double number , StringBuffer toAppendTo ,
FieldPosition status );
public int hashCode ( );
public Number parse (String text , ParsePosition status );
}
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