Lesson 24 Keywords.

[Chewii]

You say this

*       true or true and false
*
*           true or true and false
*           true or (false)
*           true
*
*   This expression is supposed to return true
*
*   It returns false

I don't get why it is like that? because further down you also say

true or (anything) will always be true

but apparently not, explain please

 

[edo494]

its because Jass doesnt perform and's before or's(or or's before and's), but it goes in line

so "true or true and false" is actually "(true or true) and false" which is "true and false" and that is false

 

[Chewii]

oh thank you

 

[Nestharus]

Order of logical operations (like order of operations in math)

not
and
or

JASS just totally ignores order of operations, it's like

3+3*3 = 18, when the correct answer is 12 : p.

Something else to test is short circuit logic. Does JASS follow short circuit logic?

true or AddOne()

Then display the variable. If 1 was added, it does not use short circuit logic. If one wasn't added, it does. A good test .

 

[Chewii]

Because it is true it will ignore the rest so I guess the variable wont be 1.

true or AddOne()

Thank you for the tip

 

[Nestharus]

That's only if JASS runs as it's supposed to : p. Don't assume that it follows correct logic : ). For example, Visual Basic will run through the entire thing >.>.

 

[edo494]

function test1 takes nothing returns boolean
    call DisplayTimedTextToPlayer(GetLocalPlayer(), 0, 0, 15, "Test1")
    return true
endfunction

function test2 takes nothing returns boolean
    call DisplayTimedTextToPlayer(GetLocalPlayer(), 0, 0, 15, "Test2")
    return true
endfunction

function test3 takes nothing returns boolean
    call DisplayTimedTextToPlayer(GetLocalPlayer(), 0, 0, 15, "Test3")
    return true
endfunction

function print takes string s returns nothing
    call DisplayTextToPlayer(GetLocalPlayer(), 0, 0, s)
endfunction

function Trig_aaa_Actions takes nothing returns nothing
    if test1() or test2() or test3() then
    endif
    call print("another")
    if test1() and (test2() or test3()) then
    endif
    call print("another")
    if test1() or test2() and test3() then
    endif
endfunction

//===========================================================================
function InitTrig_aaa takes nothing returns nothing
    set gg_trg_aaa = CreateTrigger(  )
    call TriggerAddAction( gg_trg_aaa, function Trig_aaa_Actions )
    call Trig_aaa_Actions()
endfunction

prints:

Test1
another
Test1
Test2
another
Test1
Test3

so it does short circuit because he didnt run all the functions

 

[Nestharus]

Perfect =), it just doesn't do order of operations, lol.

 

[themerion]

JASS just totally ignores order of operations, it's like

3+3*3 = 18, when the correct answer is 12 : p.

While I feel this borders on thread necromancy, I just want to point out that 3+3*3 is indeed 12 in JASS.

call BJDebugMsg(I2S(3+3*3)) // 12

 

[Nestharus]

Yes, math order of operations is correct, but not logical order of operations.

Order of logical operations (like order of operations in math)