C# compiler does not limit the number of digits of fractional part of a floating-point literal -
this academic purpose.
i noticed integral literals, can declare 18446744073709551615 2^64-1 or ulong.maxvalue. defining greater value produces compile-time error.
and floating-point literals, can declare them integral part 999...999 (9 repeated 308 times). declaring integral part more digits again produces compile-time error. 1 thing interests me compiler seems allow specify fractional part unlimited number of digits. practically, unlimited number of digits fractional part not make sense.
questions:
is there constant representing max number of digits internally defined c# compiler fractional part of floating-point number?
if such constant exists, why not c# compiler throw compile-time error when users specify fractional parts beyond limit?
minimal working example 1
namespace floatingpoint { class program { static void main(string[] args) { const ulong @ulong = 18446744073709551615; const double @double = 99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999.9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999; } } } minimal working example 2
using system; namespace floatingpoint { class program { static void main(string[] args) { const double x01 = 0.9; const double x02 = 0.99; const double x03 = 0.999; const double x04 = 0.9999; const double x05 = 0.99999; const double x06 = 0.999999; const double x07 = 0.9999999; const double x08 = 0.99999999; const double x09 = 0.999999999; const double x10 = 0.9999999999; const double x11 = 0.99999999999; const double x12 = 0.999999999999; const double x13 = 0.9999999999999; const double x14 = 0.99999999999999; const double x15 = 0.999999999999999; const double x16 = 0.9999999999999999; const double x17 = 0.99999999999999999; const double x18 = 0.999999999999999999; const double x19 = 0.9999999999999999999; const double x20 = 0.99999999999999999999; console.writeline(x01); console.writeline(x02); console.writeline(x03); console.writeline(x04); console.writeline(x05); console.writeline(x06); console.writeline(x07); console.writeline(x08); console.writeline(x09); console.writeline(x10); console.writeline(x11); console.writeline(x12); console.writeline(x13); console.writeline(x14); console.writeline(x15); console.writeline(x16); console.writeline(x17); console.writeline(x18); console.writeline(x19); console.writeline(x20); } } } /* output: 0.9 0.99 0.999 0.9999 0.99999 0.999999 0.9999999 0.99999999 0.999999999 0.9999999999 0.99999999999 0.999999999999 0.9999999999999 0.99999999999999 0.999999999999999 1 1 1 1 1 */ il:
.method private hidebysig static void main(string[] args) cil managed { .entrypoint // code size 302 (0x12e) .maxstack 1 il_0000: nop il_0001: ldc.r8 0.90000000000000002 il_000a: call void [mscorlib]system.console::writeline(float64) il_000f: nop il_0010: ldc.r8 0.98999999999999999 il_0019: call void [mscorlib]system.console::writeline(float64) il_001e: nop il_001f: ldc.r8 0.999 il_0028: call void [mscorlib]system.console::writeline(float64) il_002d: nop il_002e: ldc.r8 0.99990000000000001 il_0037: call void [mscorlib]system.console::writeline(float64) il_003c: nop il_003d: ldc.r8 0.99999000000000005 il_0046: call void [mscorlib]system.console::writeline(float64) il_004b: nop il_004c: ldc.r8 0.99999899999999997 il_0055: call void [mscorlib]system.console::writeline(float64) il_005a: nop il_005b: ldc.r8 0.99999990000000005 il_0064: call void [mscorlib]system.console::writeline(float64) il_0069: nop il_006a: ldc.r8 0.99999998999999995 il_0073: call void [mscorlib]system.console::writeline(float64) il_0078: nop il_0079: ldc.r8 0.99999999900000003 il_0082: call void [mscorlib]system.console::writeline(float64) il_0087: nop il_0088: ldc.r8 0.99999999989999999 il_0091: call void [mscorlib]system.console::writeline(float64) il_0096: nop il_0097: ldc.r8 0.99999999999 il_00a0: call void [mscorlib]system.console::writeline(float64) il_00a5: nop il_00a6: ldc.r8 0.99999999999900002 il_00af: call void [mscorlib]system.console::writeline(float64) il_00b4: nop il_00b5: ldc.r8 0.99999999999989997 il_00be: call void [mscorlib]system.console::writeline(float64) il_00c3: nop il_00c4: ldc.r8 0.99999999999999001 il_00cd: call void [mscorlib]system.console::writeline(float64) il_00d2: nop il_00d3: ldc.r8 0.999999999999999 il_00dc: call void [mscorlib]system.console::writeline(float64) il_00e1: nop il_00e2: ldc.r8 0.99999999999999989 il_00eb: call void [mscorlib]system.console::writeline(float64) il_00f0: nop il_00f1: ldc.r8 1. il_00fa: call void [mscorlib]system.console::writeline(float64) il_00ff: nop il_0100: ldc.r8 1. il_0109: call void [mscorlib]system.console::writeline(float64) il_010e: nop il_010f: ldc.r8 1. il_0118: call void [mscorlib]system.console::writeline(float64) il_011d: nop il_011e: ldc.r8 1. il_0127: call void [mscorlib]system.console::writeline(float64) il_012c: nop il_012d: ret } // end of method program::main
- yes, aren't decimal digits
- specification of fractional parts beyond ability represent them easy, when specification decimal , representation binary.
0.3requires approximation.
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