Does Excel evaluate both result arguments supplied to the IF function? - excel

Excel's if function takes three arguments, a condition, an if-true value, and an if-false value. Does Excel work out the value of all three arguments, or does it only work out the value of the condition and the corresponding result?
Clarification: I'm not wondering what the result of the if will be, I'm wondering whether or not it calculates the value of all arguments before calculating the result of the function.
This is equivalent to asking whether or not the if function uses lazy or strict evaluation. For example, the following pseudocode:
x = 5;
print x>2 ? "Bigger" : "Smaller" + 1/0
would throw a divide-by-zero exception in a language with fully strict evaluation, as it would evaluate the 1/0, even though the result wouldn't be required for the ?: operator.
In a lazy-evaluation language, the ?: operator would evaluate x>2 before even deciding which expression to evaluate.
The problem is that in Excel, 1/0 produces a legitimate value (which happens to be #DIV/0!) that can exist in expressions. Therefore, simply calling =if(true,1,1/0) doesn't show whether Excel is evaluating the 1/0 or not.

Very east to test
? iif(true, 1, 1/0) 'run-time error: division by zero
I'm assuming you really mean iif() - in VBA this does not "short-circuit", so you should use If..Then..Else..End If in cases where that could be a problem.
Ok - testing what you really asked:
'In a VBA module
Function TruePart()
MsgBox "True part"
TruePart = "True"
End Function
Function FalsePart()
MsgBox "False part"
FalsePart = "False"
End Function
In a cell: =IF(TRUE,truepart(),falsepart())
Only get one msgbox per calculation of the IF() cell.
As further validation, this gives you two msgbox - one for each:
Sub Tester()
Debug.Print IIf(True, TruePart(), FalsePart())
End Sub

It does not.
Excel 2013 only evaluates the necessary code.
I had a very complex and time consuming cell formula to copy through a couple hundred thousand rows. It would take a few hours to calculate. But fortunately, it was easy to determine based on some other criteria when the result would be zero.
So using an If Statement to avoid the calculation when other criteria suggested it must be zero, and performing the calculation only when necessary sped up the process immensely, cutting processing time to about 10% of the previous.
If Excel were evaluating both expressions, the If Statement would only have added complexity and time.

A couple simple tests:
=IF(TRUE,1,1/0)
=IF(FALSE,1/0,1)
Neither results in a div/0 error, so one could conclude only the corresponding result of the condition is actually evaluated. Obviously the condition itself also must be evaluated.
In more complex formulae you could also use the Evaluate Formula tool to watch how IF statements are parsed.

Excel seems to use eager evaluation for the IF() function (i. e. always evaluates all three arguments). To test without VBA, turn on automatic workbook calculation and enter into a new workbook's cell:
=IF(TRUE, 0, RAND())
Save and close workbook. Open the workbook again and close again, and Excel will show the "save changes" prompt because volatile function RAND() has been evaluated.
Change RAND() to 1 and Excel does not show the prompt.

I have the opposite answer to Tim, based instead on XL 2010 If Function:
=IF(TRUE,1,1/0)
doesn't yield a #DIV/0 error,
=IF(FALSE,1,1/0)
does. Also, my reading implies that only the appropriate condition is evaluated.

Related

Multiple IF statements in Excel not working

I would like to set a multiple IF statement for my formula.
The reason behind it is, that I need to switch off the values (mark them as N/A and NA) which are equal to the other certain values as follows:
LP372/24/60+1=($NO372-720)/24/60+1 => mark them as N/A - the values, which don't happen during the midnight
and
LP372/24/60+1=$NO372/24/60+1 => mark them as NA - the values, that don't happen during the midday
The problem is, that I can't keep them under one IF statement, because I need the division.
So far I used only one IF statement (the nested one), which looks as follows:
=IF(OR((LP372/24/60+1)=(($NO372-720)/24/60+1), OR((LP372/24/60+1)=($NO372/24/60+1))),"N/A",LP372/24/60+1).
The value of NO372 corresponds to the rough time of the local midday. Substracting the 720 we are getting the rough midday for this location, knowing that the single day counts 24 hours x 60mins = 1440mins.
The formula above gives a nice result, but without the division between midday and midnight, which I am talking about.
Following my older query about the similar issue:
Double nested IF statement formula in Excel
I tried to solve it like this:
=IF(COUNTA(E1116:E1481),IF(OR((LP372/24/60+1)=(($NO372-720)/24/60+1),OR((LP372/24/60+1)=($NO372/24/60+1))),"N/A",LP372/24/60+1),"NA")
where the range E1116:E1481 corresponds to the whole year period (1.01 - 31.12).
Unfortunately I got nothing, similarity to this formula:
=IF(COUNTA(E1116:BC1116),IF(OR((LP372/24/60+1)=(($NO372-720)/24/60+1),OR((LP372/24/60+1)=($NO372/24/60+1))),"N/A",LQ510/24/60+1),"NA"),
where the E:1116:BC1116 range correspond to the all columns - circumstances as occur on January 1.
This formula was still not correct.
I found something on the web about the multiple IF statements:
which led me to the following formula
=IF((LP372/24/60+1)=(($NO372-720)/24/60+1);"N/A";IF((LP372/24/60+1)=($NO372/24/60+1);"NA")LP372/24/60+1)
Unfortunately again not correct.
The last attempt was an answer provided here:
Multiple IF statements in Excel
on which basis I built up another formula
=IF((LP372/24/60+1)=(($NO372-720)/24/60+1),"N/A",LP372/24/60+1,IF((LP372/24/60+1)=($NO372/24/60+1),"NA"))
this time Excel said, that I've entered too many arguments.
Is there a way to set up multiple IF statements?
I need to:
make the values equal to midnight as N/A,
make the values equal to midday as NA
keep the other values as they stand
This question was answered in the comments, but I thought I would add an answer with an example of how to nest IF statements for anyone that found this question because they are having issues with nesting IF statements.
When you add an IF statement to a formula in excel, you have to keep in mind that IF statements have 3 parts separated with commas:
The first value is the condition you are going to check
The second value is the value you want returned if that condition is true
The third value is the value you want returned if that condition is false
So here's an example that illustrates that:
=IF(condition to check, value if condition is true, value if condition is false)
Here is an example IF statement:
=IF(A1="Hello","World","something else")
If you are getting FALSE returned then your IF statement probably looks like this:
=IF(A1="Hello","World")
Notice that there are only 2 values inside this IF statement: the condition you are checking (A1="Hello") and what you want displayed if that is true ("World"). FALSE would be displayed if the value in A1 is something other than Hello because you haven't included the third value in the IF that defines what you want displayed if A1 is not Hello (this value is listed as something else in the example above)
It's best to try and avoid nesting IF statements if you can because they can be hard to keep track of. I would suggest using AND() or OR() instead if you can. They are very similar to each other, you list multiple conditions within the parens separated by commas that you will be checking against, and both evaluate to either True or False. The only difference is that for AND() every condition within the parens needs to be true for it to evaluate to True where OR() only one of the conditions listed in the parens needs to be true for it to return True.
So, for example, if you wanted to display World if A1 is Hello or Hi and you were to use nested IF statements it would look like this:
=IF(A1="Hello","World",IF(A1="Hi","World","something else"))
which in my opinion is really ugly. however, if you used OR() instead of nesting IF statements it would look like this:
=IF(OR(A1="Hello",A1="Hi"),"World","something else")
AND() works the same way, but instead of just needing one condition within the parens to be true to return True as OR() does, with AND() all conditions inside of the AND() need to be true to display your value instead of just one. here's an example AND():
=IF(AND(A1="Hello",B1=""),"World","something else")
in this case "World" would be displayed only if A1 is Hello AND B1 is empty
for both AND() and OR() you can have more than just 2 values inside if you need to check for more than 2 conditions, you just need to separate them each with commas, like this:
AND(condition1, condition2, condition3, ....)
OR(condition1, condition2, condition3, .....)
but, if you have to use nested IF statements, the easiest way I've found is to type IF( , , ) first thing to make sure you are allowing for all 3 values that need to be inside of the IF and you have the right amount of values inside the IF. If you are getting the message You've entered too many arguments for this function it is because you have entered more than 3 values inside your IF, like this:
=IF(A1="Hello","World","something else","this value is causing the issue")
so, to properly nest an IF in your formula, type IF( , , ) first off where you want the IF statement to be in your formula and then just fill in the blanks, then you avoid entering too few values which results in FALSE being displayed if your condition is not true or You've entered too many arguments for this function because you entered more than 3 values in your IF
Hope this helps to understand IF statements and how to nest them properly.

How to use IF function with 3 arguments while ignoring blanks

Okay so my question is how do i use IF with 3 arguments while one of the arguments is "Ignore blanks".
If A1 is "Escalation_complaint or "Escalation_request" B1 must show "Escalated".
If A1 is any other text, B1 must show "Solved"
If A1 is blank, B1 must remain empty.
Can someone please help me figure this out?
Your first test must be whether the A1 is empty or not. This must be the first because if you test whether an empty string is contained in another string the answer is always yes. =SEARCH("","Something") returns 1. So, How do you test for an empty cell? I recommend Excel's COUNTA() function but you may prefer testing for "". So, let's say, your first test is this.
=IF(COUNTA(A1), True, False)
Some would say IF(COUNTA(A1)>0, True, False) and that is equivalent. The simple IF(COUNTA(A1) tests for non-zero. Any number other than zero returns True.
So, now you got your basic function. What's supposed to happen if the result is True? What do you want to happen if the result is False? The latter is easy. If the result is False you want a null string returns. So, now your formula looks like this:-
=IF(COUNTA(A1), True, "")
Observe that we simply replaced the False with the desired output. So, what do you want to happen if A1 has something in it, if the first test resulted in True? There are two possibilities. That makes the problem solvable with a single IF. IF A1 has something starting with "Escalation" in it the result should be "escalate", else it should be "solved". So, how do you test for cell content?
=Find("escalation", A1) will not find "Escalation" (with a capital E). Therefore I recommend SEARCH(), which does.
=SEARCH("escalation", A1) should return 1. If it returns 1 your problem is solved because if it returns any other number its not "escalated" but "solved". Unfortunately, there is a third option. It might return an error. In fact it will return an error every time the word isn't found. That gives you a 3-way possibility (1, bigger than 1, or Error) which can't be solved with a single IF. So, I suggest to avoid the error.
=Find("escalation", A1 & "escalation") will find the word "escalation" every time. But it will find it in first position only if the conditions for "Escalate" is met. Therefore the formula for the True condition in the basic formula must be this:-
IF(SEARCH("escalation", A1 & "escalation") = 1, "Escalated", "Solved")
That's it. Assemble the second IF into the first and you're done.
So, using two if(), and minimising the testing you need :
=IF(left(A1,3)="Esc","Escalated",IF(A1="","","Solved"))
Edit: Based on a comment to another answer, if testing for "esc" only could lead to problems then how about:
=IF(left(A1,5)="Escal","Escalated",IF(A1="","","Solved"))
Which will avoid words like "escaped" or "escargot"...
If you know that the text will always be Escalation_complaint or Escalation_request, you can do this with a nested IF query. =IF in Excel takes three parameters: what to verify, result if true, and result if false. You can have another IF statement in the what to do if it returns false section. We can also do an OR() statement to verify both Escalation_complaint and Escalation_request. The result looks like this:
=IF(OR(A1="Escalation_complaint",A1="Escalation_request"),"Escalated",IF(A1="","","Solved"))
The order here is important because you want the "for all other cases" to be in the final IF statement.
If you have a situation where you could also have "Request_escalation" or "complaint_escalation", you should make a more general solution that uses SEARCH or FIND which would allow you to do a more general lookup that allows for more values without having to hardcode them. Here is an example that makes it possible to find the word Escalation anywhere in the cell:
=IF(IFERROR(SEARCH("escalation",A1,1),0)>0, "Escalated", IF(A1="","","Solved"))
Excel have maximum 30 arguments in a formula.
= if (A1=1, "True",if(B1>2,"True", "false"))
Understand this pattern. easy way.
If you no longer understand this, or if your problem has not been resolved, attach a file or screenshot that relates to your problem.

is Excel function OR() incorrect?

Is there any reason in an Excel spreadsheet the expression OR(TRUE,#N/A) returns #N/A ?
How can we make it work the way we learned at school ie. OR(TRUE, whatever) should equal TRUE ?
so that we can evaluate a logical expression correctly even if not all parameters are known at the time of running, if those unknown are not really required.
Thank you
PS.
i use #N/A where the input is not known yet, it is not meant to be
an error. For instance
"=OR(turnover>1000000,leadtime>90,AND(turnover>500000,leadtime>30),AND(turnover>200000,leadtime>60))"
indicates an item needs special attention either because its
turnover is high or because its lead time is long but i don't
always have inputs for both. Sometimes one of two should suffice.
N/A is used when not known because i haven't found anything better than that. Tried "Unknown" string and AND(TRUE,"Unknown")
returns TRUE, which is not what it should be
i have many expressions which are more complicated than just
OR(x1,x2) so instead of trapping every parameter for error i have
written an udf OOR where OOR(TRUE,whatever even if error) = TRUE.
Just wondering if Microsoft has a better approach i don't know
You can wrap the logicals in an IFERROR that returns FALSE:
=IF(OR(IFERROR(A1=1,FALSE),IFERROR(B1=1,FALSE)),TRUE,FALSE)
You cannot compare to an error without throwing an error. Use ISERROR or ISNA on the cell to see if it contains an error.
=IF(OR(A1=TRUE,ISERROR(A1)), <something if true>, <something if false>)
In the above, you don't need to say A1 = TRUE, simply A1 will return true or false.

Is Excel's 'Dependency-Chain' increased or decreased?

I have a formula which includes the use of a UDF that calculated National insurance liability (a tax in the UK). It is complex and use many times, so it is slow to calculate.
Some of the cells it gets the salary from are unused, and so have zeros in.
is the formula:
=NI_Calc(D9,A1:A5,B1:B5,F1:F5)
better than:
=IF(D9=0,0,NI_Calc(D9,A1:A5,B1:B5,F1:F5))
i.e. does the IF function instruct Excel not to calculate the UDF 'NI_Calc'? thereby reducing the load.
or does Excel calculate the UDF anyway and the IF function just adds to its load?
Thanks
the IF statement in excel will not calculate the second part of the statement if the first part satisfies the condition. From the docs...
"When Excel finishes evaluating the first condition, the results may match (in which case the Approve result appears) or they may not. If it's not a match, the parent IF function has already run through two of its three arguments. You still have two possible outcomes! You complete your formula by nesting your second IF function in the third argument (value_if_false) of the parent IF. The nested IF becomes the self-contained third argument of the parent IF. When the nested IF finishes evaluating, it decides between the two remaining possible outcomes, displays the result, and the function ends."
https://support.office.com/en-us/article/IF-function-69aed7c9-4e8a-4755-a9bc-aa8bbff73be2
EDIT: Actually, thats not really massively clear...
this answer Does Excel evaluate both result arguments supplied to the IF function? shows it better

Array evaluation of find_text argument in SEARCH() function

Say I have the following:
Entering the following formulas in cell C1 and then clicking Evaluate Formula->Evaluate produces very different results:
Formula 1: B$1:B$5 evaluates as non-array
{=SEARCH(B$1:B$5,A1)}
Formula 2: B$1:B$5 evaluates as an array
{=IF(SEARCH(B$1:B$5,A1),"")}
Why, exactly, is this? What is the cause of this behavior? If possible, please provide other examples using other Excel functions to illustrate what is happening here.
Parenthetically:
My question came about while experimenting with the accepted answer to this question.
In general, an array of values will only be returned by a worksheet function given that the following two conditions are satisfied:
1) The formula in question is either in itself capable of returning an array of values, or else is contained within a larger set-up of several functions, one or more of those which precede the function in question (and therefore act upon it) having that property. Whether that capability is something which requires coercion (i.e. via array-entry (CSE)) or is an in-built feature of the function is not important in terms of the answer you are seeking.
2) The array generated must be passed to a further function for processing. Excel is more teleological than you think: it has no great belief in returning an array of values as an end in itself.
As for your example, it's not that SEARCH, when array-entered, isn't capable of processing arrays (it is). It's more that there is no further function incited which is to act upon that array. In the IF version, there is precisely that, though again, if you process that one more time you'll find that your current array is reduced to just the first element in that array. Wrap a further function around the IF, e.g. SUM, and you'll be able to go one step further, and so on and so on.
And here is a major difference between evaluating formulas via the Evaluate Formula tool, and repeated "evaluation" via selecting various parts of the function in the formula bar and pressing F9.
The latter will always return an array of values, whether the above two conditions are satisfied or not. However - and not many people realise this - the "evaluation" so obtained can, ultimately, lead to incorrect results, and so should only be used providing one is aware of its limitations.
Take the following example, for instance:
With A1:A10 empty, the formula:
=SUMPRODUCT(0+(A1:A10=""))
correctly returns 10.
Now select just the part A1:A10 in the formula bar and press F9. Excel, being forced to "evaluate" the range, returns:
=SUMPRODUCT(0+({0;0;0;0;0;0;0;0;0;0}=""))
which, on further processing, results (correctly, it would seem) in the quite different result of 0.
Regards

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