A fundamental data type that holds double-precision floating-point numbers in IEEE format. A Double variable is stored as a 64-bit (8-byte) number ranging in value from –1.79769313486231E308 to –4.94065645841247E–324 for negative values, from 4.94065645841247E–324 to 1.79769313486231E308 for positive values, and 0. The type-declaration character is # (ANSI character 35).