Question about 'if's

[Ofel]

When I write:

if IsUnitEnemy(u, p) and IsUnitType(u, ut) then
    // 'then' actions
endif

and u is not an enemy, will IsUnitType be skipped?

 

[IcemanBo]

Well it depends. If you have two boolean expressions connected with a logical and
then the second one will be only evaluated if the first one returns true.

if true and false then
    // both are evaluted
endif

if false and false then
    // first is evlauted
    // second is ignored
endif

So, it depends if IsUnitEnemy(u, p), or as you want to change it, if not IsUnitEnemy(u, p) will be true or false.

 

[DracoL1ch]

yes, as soon as it comes to "false && " whole statement automatically being taken as false, even if it isn't supposed to

 

[Rheiko]

Even in language and reality, something that has "and" with them means both of them are necessary. (This is ignored most of the times though)
For example, "You and Her are summoned to attend the meeting".
It means both of them are summoned to attend the meeting, not just one of them.
If only one of them, that condition will not return true.
same goes with the if statement. Both conditions must be fulfilled for it to return true.
It takes both of the conditions into consideration before starting the actions of the other tasks.

 

[DracoL1ch]

Even in language and reality, something that has "and" with them means both of them are necessary. (This is ignored most of the times though)
For example, "You and Her are summoned to attend the meeting".
It means both of them are summoned to attend the meeting, not just one of them.
If only one of them, that condition will not return true.
same goes with the if statement. Both conditions must be fulfilled for it to return true.
It takes both of the conditions into consideration before starting the actions of the other tasks.

don't apply human's logic with jass
false and true or true == false (jass)

 

[Rheiko]

elaborate, please?

 

[DracoL1ch]

http://www.hiveworkshop.com/forums/...ical-ops-optimization-bug-277701/#post2809562

 

[Rheiko]

Well, damn you, Jass for differing yourself from common logic.
Also, thanks for the clarification.

Question though

if false and true then
    // this will also return false then?
endif

Edit: NVM, got the answer. Might be helpful for ofel.

 

[Wietlol]

if false and true then
!=
if true and false then

The point where this becomes interesting is:
if dothisandgivefeedback() and false then
vs
if false and dothisandgivefeedback() then

In fact, today I actually made use of this to skip a check that would fail because it would be missing from the object's fields by doing:
if ($isCustom || $widget->getRequest())
If you really want to use it is just user preference, but you should be aware of what happens in order to properly debug your code.

 

[Dr Super Good]

JASS is not a normal language. It lacks most common language features like bitwise operators and native modulus support.

It likely treats "and" and "or" as the same precedence level. It makes little difference anyway as one should be bracketing in such situations for readability.

Presented with...
A && B || C && D || E && F && G || H
Even knowing the precedence of the language (this example was C/C++) it is still confusing and can be error prone to modify as it is easy to make a mistake and modify the wrong group of terms. Imagine if the letters were large comparison terms. Imagine if there were 3 or 5 times as many terms.

Hence why it is often better for readability to bracket the terms...
(A && B) || (C && D) || (E && F && G) || H
There is absolutely no room for ambiguity if you do this.