The origin of the “double” data type

In Flutter, as in many programming languages, double refers to a data type that represents floating-point numbers. The term "double precision" is a bit of a historical artifact. It originates from the representation of floating-point numbers in computers, where a "double-precision" floating-point format uses twice as many bits as a "single-precision" format.

Here’s a breakdown:

Single-Precision vs. Double-Precision:

• Single-precision floating-point numbers typically use 32 bits, and they are represented as 1 bit for the sign, 8 bits for the exponent, and 23 bits for the significand (fractional part).

• Double-precision floating-point numbers use 64 bits, with 1 bit for the sign, 11 bits for the exponent, and 52 bits for the significand (mantissa).

Why is it called “double”?

• The term “double” in “double precision” comes from the fact that double-precision numbers use double the number of bits compared to single-precision numbers (64 vs 32 bits respectively).
• This extra precision allows for a larger range of representable numbers and provides a more accurate representation of decimal values.

Dart and Flutter:

• In Dart, which is the language used for Flutter development, the double data type is used to represent double-precision floating-point numbers.
• Dart follows the IEEE 754 standard for floating-point arithmetic, which specifies the representation and behavior of floating-point numbers.

Decimal Point Representation:

• Numbers with decimal points are commonly referred to as “floating-point” numbers because the decimal point can “float” to different positions in the number.
• The term “double” is historical and doesn't mean that the numbers have exactly twice the precision of integers. It signifies that the numbers use a double-precision floating-point format.

In summary, a double in Flutter represents a double-precision floating-point number, which is a way of representing numbers with decimal points using a specific format that allows for a wide range of values and precision. The term "double" comes from the fact that it uses double the number of bits compared to single-precision floating-point numbers.