| Posted: 09:58am 23 Nov 2025 |
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To optimise performance do not use the same name for local variables in nested subroutines.
Variables are created in a hash table. So by definition if you use i as an index in a subroutine called by a subroutine that also uses i. There will have been a hash table collision that the firmware resolves by looking for the next free slot. This is completely benign but does take extra time: not a lot but some.
Also, it is very slightly quicker if variables are typed at declaration rather than being typed with a suffix
Demo 1
fred
'
Sub fred
Local i%=22,ii%=23
bert
Print i%,ii%
End Sub
'
Sub bert
Local i%,j%,ii%,jj%
Timer =0
For i%=1 To 100000
ii%=i%
Next
Print Timer
Timer =0
For j%=1 To 100000
jj%=j%
Next
Print Timer
End Sub
Demo2
Option explicit
Option default integer
fred
'
Sub fred
Local i=22,ii=23
bert
Print i,ii
End Sub
'
Sub bert
Local i,j,ii,jj
Timer =0
For i=1 To 100000
ii=i
Next
Print Timer
Timer =0
For j=1 To 100000
jj=j
Next
Print Timer
End Sub
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