Number is often used in application logic.Many times we need display the number in the form of string which is user customed.For example,suppose we know a number 90700.87008.Perhaps you hope to display the number in the form of 9.07e+4.Perhaps you also hope to display the 0.5623 in the form of 56.2%.

All of above may be called number format.So how can we format a number in the customed form? To resove this propblem,we refer to DecimalFormat class in J2SE of Java language of Sun.

In the below,we quote the documentation of DecimalFormat class of J2SE of Sun.

Symbol	Location	Localized?	Meaning
0	Number	Yes	Digit
#	Number	Yes	Digit, zero shows as absent
.	Number	Yes	Decimal separator or monetary decimal separator
-	Number	Yes	Minus sign
,	Number	Yes	Grouping separator
E	Number	Yes	Separates mantissa and exponent in scientific notation. Need not be quoted in prefix or suffix.
;	Subpattern boundary	Yes	Separates positive and negative subpatterns
%	Prefix or suffix	Yes	Multiply by 100 and show as percentage
\u2030	Prefix or suffix	Yes	Multiply by 1000 and show as per mille
¤ (\u00A4)	Prefix or suffix	No	Currency sign, replaced by currency symbol. If doubled, replaced by international currency symbol. If present in a pattern, the monetary decimal separator is used instead of the decimal separator.
'	Prefix or suffix	No	Used to quote special characters in a prefix or suffix, for example, "'#'#" formats 123 to "#123". To create a single quote itself, use two in a row: "# o''clock".

The usage of patterns in JsJava is similar to that in Java.But in jsjava2.0, "#" "," "'" "¡è" ";" are not supported.e.g as follows:

<script src="jsjava-2.0.js"></script> <script> var nf=new DecimalFormat(); nf.applyPattern("000.000%"); var res=nf.format(-0.893566); document.write(res+"<br>"); nf.applyPattern("0000.00"); var res=nf.format(-53.385967); document.write(res); nf.applyPattern("0000.000E00"); var res=nf.format(53.385967); document.write(res+"<br>"); </script> The display is : -89.357% -53.39 5338.597e-2

Use more,understand more!