Float and double range and precision

1. Scope

The float and double ranges are determined by the number of digits of the index.
The float index has eight digits, while the double index has 11 digits. The distribution is as follows:
Float:
1bit (symbol bit) 8 bits (index bit) 23 bits (tail bit)
Double:
1bit (symbol bit) 11 bits (index bit) 52 bits (tail bit)
Therefore, the float index range is-127 ~ + 128, while the double index range is-1023 ~ + 1024, and the index bit is divided by complement code.
The negative index determines the smallest non-zero number of absolute values that floating point numbers can express. The positive index determines the maximum number of absolute values that floating point numbers can express, that is, the value range of floating point numbers.
Float range:-2 ^ 128 ~ + 2 ^ 128, that is,-3.40e + 38 ~ + 3.40e + 38; the double value range is-2 ^ 1024 ~ + 2 ^ 1024, that is,-1.79e + 308 ~ + 1.79e + 308.