how to not enter if statement inside a loop if it have been executed - excel

Question

I have a for loop, and inside it i have if statement.
In my Excel I have a list that contains each value one time. Once I found it i don't want the code to even check the conditional, i want it to skip this part of the if statement completely each time the loop is executed, is it possible?
Here is my code and list:
the first iteration of the loop will find that "c" is the value so it will do what inside it (xc = i)
I don't want the code to even check "ElseIf Cells(1, i) = "c" again, like the following image, is this possible?
code as text:
Sub test()
Dim i, xa, xb, xc As Integer
For i = 1 To 5
If Cells(i, 1) = "a" Then
xa = i
ElseIf Cells(i, 1) = "b" Then
xb = i
ElseIf Cells(i, 1) = "c" Then
xc = i
End If
Next i
End Sub

Answer 1

My initial interpretation of your need was "if the code hits 'c' again, just don't act".
To do so, you could modify the logic as follows:
ElseIf (xc = 0) And (Cells(i, 1) = "c") Then
This way, as soon as xc is set, the first boolean expression would be False, and the overall condition would not ever be met again. As mentioned by #TimWilliams, VBA would still evaluate the second boolean expression, unlike other languages that feature short-circuiting options. #Gene's answer describes a way around this. Typically, for better performance, you would evaluate the simple conditions first, before resorting to costly ones.
Additional notes
In VBA, you must give a type to each variable. In your Dim line, only xc is an Integer, while the other variables are Variants.
An unqualified Cells() call operates on the currently active worksheet, which might not be the expected one. Suggestion: qualify Cells() with the CodeName of your worksheet. The CodeName is what you see or specify under a worksheet's (Name) property as seen from the Visual Basic editor. For example, if (Name) is Sheet1, use Sheet1.Cells(). This will only work if the code resides in the same workbook as Sheet1. If the code is behind the worksheet itself, you can even use Me.Cells().
When dealing with cell values as your code does, VBA is (silently) being nice and understands that, among the numerous properties of the Range class, Value is what you are interested in. It is better practice, however, to explicitly state the target property, such as in Sheet1.Cells(i, j).Value.
EDIT
Knowing the values will be distinct and that there are about 60 of them, I suggest you simply use a Dictionary, as shown below, to get each value's row in one go, without a cascade of Ifs:
Option Explicit
Sub test()
Dim i As Integer
Dim dict As Object 'Scripting.Dictionary
Set dict = CreateObject("Scripting.Dictionary")
For i = 1 To 5
dict(Cells(i, 1).Value) = i
Next
Debug.Print dict("a") '4
Debug.Print dict("b") '2
Debug.Print dict("c") '1
'Etc.
End Sub

Answer 2

if i understood your question you can try this code:
Sub test()
Dim i, xa, xb, xc As Integer
Dim a, b, c As Boolean
a = False
b = False
c = False
For i = 1 To 5
If Cells(i, 1) = "a" And a <> True Then
xa = i
a = True
ElseIf Cells(i, 1) = "b" And b <> True Then
xb = i
b = True
ElseIf Cells(i, 1) = "c" And c <> True Then
xc = 1
c = True
End If
Next i
End Sub
Boolean variable is setted true for example only when the cells(i,1)="a" and after the next "a" value are skipped...
hope this helps

Answer 3

I just wanted to "mod" Ferdinando's code so it's a bit more "readable", I think. The main (the substantive) difference between this version and Ferdinando's or Excelosaurus' is that the cell is not even tested once the value is detected. Remember that the question was: I don't want the code to even check "ElseIf Cells(1, i) = "c" again... So, this version does exactly that.
Sub test()
Dim i As Integer, xa As Integer, xb As Integer, xc As Integer
Dim aFound As Boolean, bFound As Boolean, cFound As Boolean
Dim r As Range
For i = 1 To 5
Set r = Cells(i, 1)
If Not aFound Then
If r = "a" Then xa = i: aFound = True
ElseIf Not bFound Then
If r = "b" Then xb = i: bFound = True
ElseIf Not cFound Then
If r = "c" Then xc = i: cFound = True
End If
Next i
End Sub

Answer 4

I don't like the idea of 60 ElseIfs. Please examine the code below. In order to test it, create a worksheet called "TestSheet" and enter your A1:A5 to cells H2:H6.
Sub TestSpike()
' 06 Jan 2019
Dim Rng As Range
Dim Items As Variant
Dim Spike As String
Dim Tmp As String
Dim i As Integer
Dim R As Long
Items = Split("c|b|0|a|1", "|")
With Worksheets("TestSheet").Columns("H")
For R = 2 To 6
Tmp = CStr(.Cells(R).Value)
If InStr(1, Spike, Tmp, vbTextCompare) = 0 Then
Spike = Spike & "|" & Tmp
On Error Resume Next
i = Application.WorksheetFunction.Match(Tmp, Items, 0)
If Err Then
MsgBox Tmp & " wasn't found in Array"
Else
MsgBox "i = " & i & " = Item " & Tmp
End If
End If
Next R
End With
End Sub
The code has a "Spike". Each item is first checked against the Spike. If it is found there no further tests are carried out. Else, it is added to the Spike.
New items, after being added to the Spike, are checked against the Array "Items" which would hold your 60 elements, separated by Chr(124) thus, Split("c|b|0|a|1", "|"). I use the worksheet function MATCH to look for the item in the array. The result is an index number (or an error, if not found). You can use this index number in a Select Case statement to process each item distinct from others, basically the same way as you now process it when the If statement returns True.
One idea you may find useful with this kind of setup is to use the index from the Match function to return a value from another array. The other array might, for example, contain function names and you use Application.Run to call a different function for each item. This would run significantly faster than examining 60-odd Select Case statements.