MQL4 StringToDouble alters the value of the variable?

External question — Stack Overflow Stack Exchange Author: skeptic23 Original post: https://stackoverflow.com/questions/62959865 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. MQL4 documentation states that the value limits for double type variables is: "Minimal Positive Value" = 2.2250738585072014e-308 "Maximum Value" = 1.7976931348623158e+308 See https://docs.mql4.com/basis/types/double Why does StringToDouble() alter the value converted? Am I doing one thing while expecting a different result? void OnStart() { string s1 = "5554535251504900090807060504030201"; double d1 = StringToDouble(s1); string s2 = DoubleToString(d1); Print("s2<",s2,">"); printf("%099.8f",d1); Print("s1<",s1,">"); return;<br> } Here's what I get when I run that code: s1<5554535251504900090807060504030201> d1<000000000000000000000000000000000000000000000000000000005554535251504899684469244159852544.00000000> s2<5554535251504899684469244159852544> 5554535251504900090807060504030201 amounts to 5.55454E+33 . Obviously, that doesn't even come remotely close to the 1.7976931348623158e+308 limit. What am I missing here?