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Class PrintfFormatException


public class PrintfFormatException
extends java.lang.IllegalArgumentException

Indicates malformed printf format string.

Details: Printf for Java throws a PrintfFormatException when formatting is attempted through an invalid format string. This exception almost always indicates a bug in the client code.


float tax_increase = SOME_VALUE;
	"taxes raised by %f% this year",
	new Object []
		new Float (tax_increase)

When this code is executed, the format string parser interprets the second percent character as the beginning of a second format specifier. But since the following character, 't', does not correspond to a legal printf conversion type, a PrintfFormatException will be thrown. (The correct format string should read "taxes raised by %f%% this year".)

Even if a format string is syntactically correct, a PrintfFormatException can still be thrown if variable widths and precisions are used, and the supplied values are invalid.


int dec_places = SOME_VALUE;
Stdio . printf
	"pi rounded to %d decimal places is %.*f",
	new Va_args (3)
	. add (dec_places)
	. add (dec_places)
	. add (Math.PI)
	. done ();

This code throws a PrintfFormatException if dec_places is negative.

For more information on printf formatting, see lava.clib.stdio.Printf.

See Also:
Printf, Stdio, Serialized Form

Methods inherited from class java.lang.Throwable
fillInStackTrace, getLocalizedMessage, getMessage, printStackTrace, printStackTrace, printStackTrace, toString
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

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