Javascript is not a typed language so it should come as no surprise that there are no specific integer or floating-point types, no short, long, byte, double, or any other type other languages use to define numbers. All numbers in Javascript are 64bit (8 bytes) floating point numbers which yields an effective range of 5e-324 (negative) to 1.7976931348623157e+308 (positive).
This reference will cover Javascript numeric literals and objects as well as the default Javascript Operators which manipulate those numbers.