The double type is stored as an eight-byte, double-precision, floating-point number. It represents a double-precision 64-bit IEEE 754 value.
The double type can represent numbers as large as 10308 (positive or negative) with an accuracy of about 15 digits, and as small as 10-323. The double type can also represent NaN (Not a Number), positive and negative infinity, and positive and negative zero.
This type is useful for applications that need large numbers but do not need precise accuracy. If you require very accurate numbers, consider using the Decimal data type.
The corresponding .NET Framework data type is . The double type is equivalent to the Number type.
The properties and methods of the double data type are the same as the System.Double properties and methods.
JScript defines a Number object. The double data type interoperates with Number object. Consequently, a Number object can call the methods and properties of the double data type, and a double data type can call the methods and properties of the Number object. For additional information, see Number Object Properties and Methods. Furthermore, Number objects are accepted by functions that take double data types, and vice versa.
The double data type should be used instead of the Number object in most circumstances.