Trunc Method in Delphi

Question

I am porting some code to .Net and I realized that the Trunc method is not properly working in Delphi. It doesn't account whether you are truncating a negative or positive value. It treats the argument as absolute.

Delphi

Trunc(-163.78999) returns -163

.Net Implementation

System.Math.Floor(-163.88888888888889) returns -164.

I can mimic the implementation but I am wondering if anyone has seen this before.

Thanks,

Answer 1

Delphi's Trunc function performs as designed. The documentation says (emphasis mine):

Truncates a real number to an integer.

In Delphi code, the Trunc function truncates a real-type value to an integer-type value. X is a real-type expression. Trunc returns an Int64 value that is the value of X rounded toward zero.

The .net equivalent to Delphi Trunc is Math.Truncate.

The Delphi equivalent to .net System.Math.Floor is Floor.