The Number Object As you can guess from its name , the Number object handles numbers. Mostly, there's little need to use this object, because you can just use simple numbers instead, and JavaScript is good at that. In fact, JavaScript creates Number objects from simple numbers automatically as it needs them. It's useful to know the properties and methods of the Number object, however, and you can find them in Table 19.4 in overview, its properties in depth in Table 19.5, and its methods in depth in Table 19.6. Table 19.4. Overview of the Properties and Methods of the Number Object | Properties | Methods | | constructor | toExponential | | MAX_VALUE | toFixed | | MIN_VALUE | toLocaleString | | NaN | toPrecision | | NEGATIVE_INFINITY | toString | | POSITIVE_INFINITY | valueOf | | Prototype | | Table 19.5. The Properties of the Number Object | Property | NS2 | NS3 | NS4 | NS6 | IE3a | IE3b | IE4 | IE5 | IE5.5 | IE6 | | constructor | | | x | x | | | x | x | x | x | | | Read/write | | | This property specifies the function that creates an object. | | MAX_VALUE | | x | x | x | | x | x | x | x | x | | | Read-only | | | This property holds the maximum possible numeric value JavaScript can handle, typically about 1.79E+308. | | MIN_VALUE | | x | x | x | | x | x | x | x | x | | | Read-only | | | This property holds the minimum possible numeric value JavaScript can handle, typically about 5.00E-324. | | NaN | | x | x | x | | x | x | x | x | x | | | Read-only | | | This property, "Not a Number," is a special value that indicates an arithmetic expression returned a value that was not a number. | | NEGATIVE_INFINITY | | | x | x | x | | x | x | x | x | | x | | | | | | | | | | | | | Read-only | | | This property is how JavaScript refers to negative infinity. | | POSITIVE_INFINITY | | | x | x | x | | x | x | x | x | | x | | | | | | | | | | | | | Read-only | | | This property is how JavaScript refers to positive infinity. | | prototype | | | x | x | | | x | x | x | x | | | Read/write | | | This property returns a reference to the object's prototype. You use the prototype property to provide base functionality to a class of objects. See "Using the prototype Property" in this chapter. | Table 19.6. The Methods of the Number Object | Method | NS2 | NS3 | NS4 | NS6 | IE3a | IE3b | IE4 | IE5 | IE5.5 | IE6 | | toExponential | | | | x | | | | | x | x | | | Returns: String | | | This method returns a string containing a number in exponential form. | | | Syntax: number .toExponential( digits ) , where digits is the number of digits after the decimal point. | | toFixed | | | | x | | | | | x | x | | | Returns: String | | | This method returns a string containing the number in fixed-point notation. | | | Syntax: number .toFixed( digits ) , where digits is the number of digits after the decimal point. | | toLocaleString | | | | x | | | | | x | x | | | Returns: String | | | This method returns a number converted to a string using the current locale. | | | Syntax: number .toLocaleString() . | | toPrecision | | | | x | | | | | x | x | | | Returns: String | | | This method returns a string containing a number in either exponential or fixed-point form with a specified number of digits. | | | Syntax: number .toPrecision( digits ) , where digits is the number of significant (total) digits. | | toString | | x | x | x | | | x | x | x | x | | | Returns: String | | | This method returns the number as a string. | | | Syntax: number .toString() . | | valueOf | | | x | x | | | x | x | x | x | | | Returns: Number | | | This method returns the value of the number contained by the Number object. | | | Syntax: number .valueOf() . | |