JavaScript 1.5; JScript 5.5, ECMAScript v3
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.
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.
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.
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
Number.toExponential( ), Number.toFixed( ), Number.toLocaleString( ), Number.toString( )