If, else in expression or use jython?

Archived Topics
1

Is it possible to do an If, Else If, Else in expression, or should I move to using the jython scripting for that.

Case, I have 2 inputs,4 seperate cases, one true, other one true, both false.(both true is something i’d like to catch as an error)

2

You can do a nested if like this in the expression language:

if ({input1} && !{input2}, "input 1 is true", if (!{input1} && {input2}, "input 2 is true", if(!{input1} && !{input2}, "neither is true", "both are true" )))

But a nicer way to do what you’re doing is to feed the booleans through the “binEnc” expression which will turn the two booleans into an integer (0-3):

switch(binEnc({input1}, {input2}), 0,1,2,3, "neither are true", // 00 "input 1 is true", // 01 "input 2 is true", // 10 "both are true", // 11 "impossible")

Hope this helps,

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3

Ahh, I’ve been dealing with ladder too long. Converting to base 2 never occcured to me. Thanks!

4

It’s really amazing how in 2020 we are still having issues with elif and expressions, has any made good use of the switch statement?

5

The closest expression equivalent of elif is nested if statements. It's not quite as elegant and must include a final else (unlike Python scripts):

// Start with an if.
if(condition, 1,
	// Nest if to get equivalent of elif.
	if(condition, 2,
		// With expressions you always have an else value at the end.
		0
	)
)

In most cases, binEnum would be an elegant replacement for the above nested ifs. See examples in the other thread you posted in.

The switch expression isn't a viable replacement for elif unless you're using elif to evaluate different values of a single condition.

6

That works very well, how do I add a three more tags and increment the output 3, 4, 5 ?

7 
binEnum(condition, condition2, condition3, condition4)
>>>
binEnum(true, false, false, false) -> 1
binEnum(false, true, false, false) -> 2
binEnum(false, false, false, false) -> 0
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