Cache properties in variables

[Cowper]

Hi,
I am reading a VB certificate exam book for my upcoming exam. There is one question about optimising an application that I don't understand and needs your help. The book says one tip for increasing performance is to cache properties in variables when you are using a loop. The reason is it is faster to access data stored in a variable them to access data stored in a property.

I still don't understand how it works. Could someone explain a bit more on this subject?

Many thanks

Cowper

 

[strongm]

Sure

every.time.that.vb.hits.a.dot it has to dereference the property value that follows (6 dereferences in the opening phrase of this sentence). This is a relatively slow process. As a one-off it may not be a big performance hit, but if you had a 5000 iteration loop, it would be 30000 (6*5000) slow operations.

By dereferencing the whole lot once into a variable prior to entering the loop, as in:

Wombat=every.time.that.vb.hits.a.dot

you avoid that overhead. Another alternative is to use the With construct, which achieves the same objective