Double <> Double

[walduxas]

Hi,

I have this code in my userform:

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Watch window shows, that both No3 and No4 have values equalt to -10.8. However, statement "If No3 <> No4" is also shown as true, but it should be false, because both variants have the same value. How could it be?

[quekbc]

Rounding issues perhaps between what the watch window says and what it actually is?

Perhaps try printing the number out in full to see - either by populating a cell in Excel or doing a Debug.Print

[walduxas]

"Me.Controls("Label" & 9 & "_" & i).Caption" is equal to "-10.8".
"Me.Controls("Label" & 5 & "_" & i).Caption" is equal to "4.8".
"Me.Controls("Label" & 7 & "_" & i).Caption" is equal to "2.25".

Print screens are attached.
UF1.jpg
UF2.jpg

[quekbc]

Very curious indeed. My suspicion is with how Excel deals with floating point precision when it comes to decimals (for more info http://www.cpearson.com/excel/rounding.htm).

A simple test like this fails as well

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Best option is to perhaps round it to say, 6 decimal places?

[walduxas]

Another interesting test, performed in Immediate window:

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Solved the issue with rounding to 2 decimal places.

[kev_]

Not relevant here but inadevertently storing a value as text can cause similar problems

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Result
z = 10.8 , x = 10.8 , True
q = 10.8 , x = 10.8 , False
q = 10.8 , z = 10.8 , False

amend only this line (which only changes the variable "type" for "q")

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Result now =
z = 10.8 , x = 10.8 , True
q = 10.8 , x = 10.8 , True
q = 10.8 , z = 10.8 , True

[thatandyward]

generally comparing doubles for equivalence is not good thing to do due to the way computers handle floating point maths.

this CPearson post has some good info relative to excel.

if you really want to get into the weeds then this is another good page