"Do While" "Loop" and "While" "Wend" Loop. What's the difference?
An answer I referred to is no longer visible, but this answer still holds true. While/Wend is a hangover from Basic and Do/Loop should be your preferred syntax because:
- It supports checking the condition before entering the loop
Do While [condition] ... Loop
(zero or more loop executions) - It supports checking the condition after entering the loop
Do ... Loop While [condition]
(one or more loop executions) - It supports no specific condition
Do ...(some logic) (Exit Do) ... Loop
(one or more loop executions, potentially infinite)
I don't think there is much of a difference in their execution other than the syntactical options that While Wend
is not capable of:
Do
someCode
While (someCondition)
As for speed, I did a simple test:
Sub whileLoopTest()
Dim i As Long, j As Long
Dim StartTime As Variant
i = 1
StartTime = Timer
While (i < 500000000)
j = i + 2
i = i + 1
Wend
Debug.Print "While execution time: " & Timer - StartTime
End Sub
Sub doWhileTest()
Dim i As Long, j As Long
Dim StartTime As Variant
i = 1
StartTime = Timer
Do While (i < 500000000)
j = i + 2
i = i + 1
Loop
Debug.Print "Do While execution time: " & Timer - StartTime
End Sub
Results:
While execution time: 6,429688
While execution time: 6,429688
While execution time: 6,441406
Do While execution time: 6,429688
Do While execution time: 6,449219
Do While execution time: 6,4375