Performance Impact: By Reference or By Value
 

Assuming that you're not modifying a parameter within a procedure, is there
any performance difference in passing the parameter as 'ByRef' or 'ByVal'.

For example

Dim arr as variant
arr = Array(12,40)
arr = TimesTwo(arr)

Function TimesTwo(ByRef or ByVal arr as variant)
Dim i as integer,arrTemp as variant
Redim arrTemp(ubound(arr))
For i = lbound(arr) to ubound(arr)
arrTemp(i) = 2 * arr(i)
Next
TimesTwo = arrTemp
End Function

Also can arrays only be declared as variants in situations such as this one.

Thanks,
Wayne C.

Performance Impact: By Reference or By Value
 

You can only assign an array to a variant or (exl2000 and later) to an
dynamic variant array.

I would think passing byval would require copying the array and this would
incur a penalty.

--
Regards,
Tom Ogilvy

"TheVisionThing" wrote in message
m...
Assuming that you're not modifying a parameter within a procedure, is
there
any performance difference in passing the parameter as 'ByRef' or 'ByVal'.

For example

Dim arr as variant
arr = Array(12,40)
arr = TimesTwo(arr)

Function TimesTwo(ByRef or ByVal arr as variant)
Dim i as integer,arrTemp as variant
Redim arrTemp(ubound(arr))
For i = lbound(arr) to ubound(arr)
arrTemp(i) = 2 * arr(i)
Next
TimesTwo = arrTemp
End Function

Also can arrays only be declared as variants in situations such as this
one.

Thanks,
Wayne C.

Performance Impact: By Reference or By Value
 

Interesting info, Tom, thanks.

By dynamic variant array in Excel 2000 or later, did you mean:

Dim arr as variant
Redim arr(2,2)
Redim Preserve arr(2,50)

Where only the last dimension of the array can be altered.

Regards,
Wayne C.

"Tom Ogilvy" wrote in message
...
You can only assign an array to a variant or (exl2000 and later) to an
dynamic variant array.

I would think passing byval would require copying the array and this would
incur a penalty.

--
Regards,
Tom Ogilvy

"TheVisionThing" wrote in message
m...
Assuming that you're not modifying a parameter within a procedure, is
there
any performance difference in passing the parameter as 'ByRef' or
'ByVal'.

For example

Dim arr as variant
arr = Array(12,40)
arr = TimesTwo(arr)

Function TimesTwo(ByRef or ByVal arr as variant)
Dim i as integer,arrTemp as variant
Redim arrTemp(ubound(arr))
For i = lbound(arr) to ubound(arr)
arrTemp(i) = 2 * arr(i)
Next
TimesTwo = arrTemp
End Function

Also can arrays only be declared as variants in situations such as this
one.

Thanks,
Wayne C.

Performance Impact: By Reference or By Value
 

No,
Dim arr() as Variant

as opposed to

Dim arr as Variant

However, there is no advantage to doing that and it just makes it
incompatible with xl97.

--
Regards,
Tom Ogilvy

"TheVisionThing" wrote in message
m...
Interesting info, Tom, thanks.

By dynamic variant array in Excel 2000 or later, did you mean:

Dim arr as variant
Redim arr(2,2)
Redim Preserve arr(2,50)

Where only the last dimension of the array can be altered.

Regards,
Wayne C.

"Tom Ogilvy" wrote in message
...
You can only assign an array to a variant or (exl2000 and later) to an
dynamic variant array.

I would think passing byval would require copying the array and this
would
incur a penalty.

--
Regards,
Tom Ogilvy

"TheVisionThing" wrote in message
m...
Assuming that you're not modifying a parameter within a procedure, is
there
any performance difference in passing the parameter as 'ByRef' or
'ByVal'.

For example

Dim arr as variant
arr = Array(12,40)
arr = TimesTwo(arr)

Function TimesTwo(ByRef or ByVal arr as variant)
Dim i as integer,arrTemp as variant
Redim arrTemp(ubound(arr))
For i = lbound(arr) to ubound(arr)
arrTemp(i) = 2 * arr(i)
Next
TimesTwo = arrTemp
End Function

Also can arrays only be declared as variants in situations such as this
one.

Thanks,
Wayne C.

Performance Impact: By Reference or By Value
 

Understood. Thanks.

Regards,
Wayne C.

"Tom Ogilvy" wrote in message
...
No,
Dim arr() as Variant

as opposed to

Dim arr as Variant

However, there is no advantage to doing that and it just makes it
incompatible with xl97.

--
Regards,
Tom Ogilvy

"TheVisionThing" wrote in message
m...
Interesting info, Tom, thanks.

By dynamic variant array in Excel 2000 or later, did you mean:

Dim arr as variant
Redim arr(2,2)
Redim Preserve arr(2,50)

Where only the last dimension of the array can be altered.

Regards,
Wayne C.

"Tom Ogilvy" wrote in message
...
You can only assign an array to a variant or (exl2000 and later) to an
dynamic variant array.

I would think passing byval would require copying the array and this
would
incur a penalty.

--
Regards,
Tom Ogilvy

"TheVisionThing" wrote in message
m...
Assuming that you're not modifying a parameter within a procedure, is
there
any performance difference in passing the parameter as 'ByRef' or
'ByVal'.

For example

Dim arr as variant
arr = Array(12,40)
arr = TimesTwo(arr)

Function TimesTwo(ByRef or ByVal arr as variant)
Dim i as integer,arrTemp as variant
Redim arrTemp(ubound(arr))
For i = lbound(arr) to ubound(arr)
arrTemp(i) = 2 * arr(i)
Next
TimesTwo = arrTemp
End Function

Also can arrays only be declared as variants in situations such as
this
one.

Thanks,
Wayne C.