24.128. Number: support for numbers ECMAScript v1: Object  Number 24.128.1. Constructor new Number(value) Number(value)
24.128.1.1. Arguments
value The numeric value of the Number object being created or a value to be converted to a number. 24.128.1.2. Returns When Number( ) is used with the new operator as a constructor, it returns a newly constructed Number object. When Number( ) is invoked as a function without the new operator, it converts its argument to a primitive numeric value and returns that value (or NaN if the conversion failed). 24.128.2. Constants
Number.MAX_VALUE The largest representable number.
Number.MIN_VALUE The smallest representable number.
Number.NaN Not-a-number value.
Number.NEGATIVE_INFINITY Negative infinite value; returned on overflow.
Number.POSITIVE_INFINITY Infinite value; returned on overflow. 24.128.3. Methods
toString( ) Converts a number to a string using a specified radix (base).
toLocaleString( ) Converts a number to a string using local number-formatting conventions.
toFixed( ) Converts a number to a string that contains a specified number of digits after the decimal place.
toExponential( ) Converts a number to a string using exponential notation with the specified number of digits after the decimal place.
toPrecision( ) Converts a number to a string using the specified number of significant digits. Uses exponential or fixed-point notation depending on the size of the number and the number of significant digits specified.
valueOf( ) Returns the primitive numeric value of a Number object. 24.128.4. Description Numbers are a basic, primitive datatype in JavaScript. JavaScript also supports the Number object, which is a wrapper object around a primitive numeric value. JavaScript automatically converts between the primitive and object forms as necessary. You can explicitly create a Number object with the Number( ) constructor, although there is rarely any need to do so. The Number( ) constructor can also be used without the new operator, as a conversion function. When invoked in this way, it attempts to convert its argument to a number and returns the primitive numeric value (or NaN) that results from the conversion. The Number( ) constructor is also used as a placeholder for five useful numeric constants: the largest and smallest representable numbers, positive and negative infinity, and the special NaN value. Note that these values are properties of the Number( ) constructor function itself, not of individual number objects. For example, you can use the MAX_VALUE property as follows: var biggest = Number.MAX_VALUE
but not like this: var n = new Number(2); var biggest = n.MAX_VALUE
By contrast, the toString( ) and other methods of the Number object are methods of each Number object, not of the Number( ) constructor function. As noted earlier, JavaScript automatically converts from primitive numeric values to Number objects whenever necessary. This means that you can use the Number methods with primitive numeric values as well as with Number objects. var value = 1234; var binary_value = n.toString(2);
24.128.5. See Also Infinity, Math, NaN | 