[JASS] Condition explanation please.

[Jetherit]

Can someone give me the most efficient way to do a normal condition, an "and" condition, and an "or" condition? I saw one post that said you could just say 'return Condition 1 and Condition 2 and Condition 3. Please explain them to me. Thanks in advance!

 

[PurplePoot]

function ThisIsACondition takes nothing returns boolean
    return SOMETHING
endfunction

=?

 

[AmadiTheGreat]

function ThisIsACondition takes nothing returns boolean
if something >= something
    return SOMETHING
endif
endfunction

=?

This way it actually asks something, so it becomes really a condition =?

 

[Jetherit]

Err...

I forgot to ask that you make a simple example for me. When I convert from GUI to JASS, if gives me an IF, then, else, which I know isn't the best way. So can someone give me an example of the most efficient way to do it, so I can know where to put everything, like the paranthesis and stuff.

 

[Mechanical Man]

There is a thing which bugs me when you convert the trigger to custom text, conditions are actually negated.

 

[PurplePoot]

[jass=K, simple example -- Life should be greater than 10]//Lame GUI way
function ThisIsACondition takes nothing returns boolean
if ( not ( GetWidgetLife(GetTriggerUnit()) > 10 ) ) then
return false
endif
return true
endfunction


//Proper way
function ThisIsACondition takes nothing returns boolean
return GetWidgetLife(GetTriggerUnit()) > 10
endfunction[/code]

This is talking about filters and trigger conditions, of course.

 

[Jetherit]

.

PurplePoot, shouldn't the condition return a boolean?

 

[Earth-Fury]

a condition is a boolexpr. there are 2 sub-types a boolexpr, condition and filter. the diffrence is non-existant. Condition() will return the same output for the same input, thus you never have to destroy boolexprs as Condition() will always return the same handle for the same function input.

a boolexpr is a kind-of pointer to a function that returns boolean.

a statement like "if condition then" takes a boolean-logic expression. A boolean logic expression is any combination of boolean operators like == != >= <= < > and or, that equate down to a single boolean answer of true or false.

boolean operates take an operator and an operand. In other words, "boolean expression == boolean expression" this allows you to do things like "boolean expression == boolean expression and boolean expression"

in warcraft 3, boolean expressions are evaluated in a short circut manner. this means that if an answer can be infferd from the current execution, then the rest of the expression is not executed. example:
MyFuncReturnsTrue() or ThisFuncWillNeverBeExecuted()
this is due to the fact that the second function would not need to be executed in order to know the result of the expression, so why execute it? there is an order of operations in JASS, but mostly things are executed left-to-right, including brakets.

hope this explains everything...

 

[PurplePoot]

GetWidgetLife() > 10 is a boolean. If the life is > 10, it's true and if the life is not > 10, it's false.

EDIT: Ah, I see, silly typo in my function declaration lines. Fixed.

 

[Jetherit]

Thank you everyone, hopefully now I can not get errors for every line I type..