how does the evaluation of the in an IF-statement work?

2020-02-27T14:05:17.104000Z

+1 to list of FAQ of efficient runtime optimization in Codesys V3! Because the compiler is doing almost nothing in term of code efficiency...

how does the evaluation of the in an IF-statement work?

2020-02-27T14:05:16.758000Z

Thanks a lot!

For the sake of completeness let's mention that for the OR statement there is also a corresponding OR_ELSE statement

how does the evaluation of the in an IF-statement work?

2020-02-27T14:05:16.406000Z

Hi.
Use AND_THEN operator.
https://help.codesys.com/webapp/_cds_op ... n=3.5.15.0 m

how does the evaluation of the in an IF-statement work?

2020-02-27T14:05:16.030000Z

I'm looking for runtime optimizations and have the following problem, which I can't find any answer to in the documentation:

Let's assume, I have multiple conditions for an IF-statement, e.g.

var1 := FALSE;
var2 := (whatever);
IF var1 AND var2 THEN
    ; // some code
END_IF

Is ```

var1 AND var2

evaluated in any case? or does it abort the evaluation as soon as it sees that

var1 = FALSE

```?

Reason: Before I evaluate a complex IF-condition (var2), I would like to pre-check, if this is necessary (var1). The second condition is expensive but is not required in 99% of the cases.

PS: Does anybody have a collection of such runtime optimization hints?

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how does the evaluation of the in an IF-statement work?

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how does the evaluation of the in an IF-statement work?