From QB64.org wiki
CDBL converts a value to the closest DOUBLE-precision value.
- doubleValue# = CDBL(expression)
- expression is any TYPE of literal or variable numerical value or mathematical calculation.
- Rounds to the closest DOUBLE floating decimal point value.
- Also can be used to define a value as DOUBLE-precision up to 15 decimals.
Example: Prints a double-precision version of the single-precision value stored in the variable named A.
A = 454.67 PRINT A; CDBL(A)
- The last 11 numbers in the double-precision number change the value in this example, since A was previously defined to only two-decimal place accuracy.