Section 24.137. Number.toPrecision( ): format the significant digits of a number


24.137. Number.toPrecision( ): format the significant digits of a number

ECMAScript v3

24.137.1. Synopsis

number.toPrecision(precision)

24.137.1.1. Arguments

precision

The number of significant digits to appear in the returned string. This may be a value between 1 and 21, inclusive. Implementations are allowed to optionally support larger and smaller values of precision. If this argument is omitted, the toString( ) method is used instead to convert the number to a base-10 value.

24.137.1.2. Returns

A string representation of number that contains precision significant digits. If precision is large enough to include all the digits of the integer part of number, the returned string uses fixed-point notation. Otherwise, exponential notation is used with one digit before the decimal place and precision-1 digits after the decimal place. The number is rounded or padded with zeros as necessary.

24.137.1.3. Throws

RangeError

If digits is too small or too large. Values between 1 and 21, inclusive, will not cause a RangeError. Implementations are allowed to support larger and smaller values as well.


TypeError

If this method is invoked on an object that is not a Number.

24.137.2. Example

 var n = 12345.6789; n.toPrecision(1);   // Returns 1e+4 n.toPrecision(3);   // Returns 1.23e+4 n.toPrecision(5);   // Returns 12346: note rounding n.toPrecision(10);  // Returns 12345.67890: note added zero 

24.137.3. See Also

Number.toExponential( ), Number.toFixed( ), Number.toLocaleString( ), Number.toString( )




JavaScript. The Definitive Guide
JavaScript: The Definitive Guide
ISBN: 0596101996
EAN: 2147483647
Year: 2004
Pages: 767

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net