Comparing two "Double" variables with -eq/-ne does not validate if number is creater than 2 digits
Note that this isn't an issue with Powershell, it's simply a problem that exists with floating point arithmetic. You can reproduce the same behavior in C#
double d = 336.1;Console.WriteLine((d + .1) == 336.2); // FalseThe problem is that 336.1 + .1 is not actually equal to 336.2. You can prove this by dumping the raw bytes for the 2 values
unsafe { double d1 = 336.1; double d2 = d + .1d; double d3 = 336.2; Console.WriteLine(*(long*)(&d2)); Console.WriteLine(*(long*)(&d3)); }Prints
46446221091397435404644622109139743539Notice that the last 2 bytes are off by 1 value. As to why this is the case someone who deals more with floating point arithmetic would have to say. In general though you should be careful when comparing floating point values. Instead of strict equality it's better to check that they are within a specific range
if (Math.Abs(d2 - d3) <= .01)) { ...}
Try typecasting your variables as [System.Decimal]How to properly compare doubles in powershell?http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html