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This question already has an answer here:

I have a simple if conditional like so,

if (gl.Node.moveUp.call(this) && this.parent._currentScene()) {
    // Do something
}

Both functions return a boolean, does the condition get evaluated in order?

gl.Node.moveUp alters something within the object calling it, which I would still like to happen even if _currentScene returns false.

So in pseudo code if the condition output was something like

if (true && false) {

}

Would the call to gl.Node.moveUp still get executed and alter the calling object or because the overall condition evaluates to false does javascript do a roll back?

Would it be better to wrap it into two if conditions like below?

if (gl.Node.moveUp.call(this)) {

     if (this.parent._currentScene()) {

     }
}
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You have 666 reputation score now, why not ask the devil? (sorry for non-constructive comment, could not help myself) –  Jan Turoň Jun 9 '13 at 20:01
 
Should take you three seconds to figure this out with a simple test -> FIDDLE, and no, the second function does not run if the condition fails after the first function has returned a boolean. –  adeneo Jun 9 '13 at 20:03
 
@adeneo That was not my question –  GriffLab Jun 9 '13 at 20:05
1  
Yes it was, if the first function returns true, the second function gets called, and whatever that function does, it does, there are no "rollbacks"! –  adeneo Jun 9 '13 at 20:07
 
@adeneo "Would the call to gl.Node.moveUp still get executed and alter the calling object or because the overall condition evaluates to false does javascript do a roll back?" –  GriffLab Jun 9 '13 at 20:19
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marked as duplicate by thejh, Stewie, hexblot, Jeremy J Starcher, Seki Jun 10 '13 at 9:10

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

2 Answers

up vote 1 down vote accepted

If the first function returns false the second function will be called, otherwise it steps out our in the else block. Even the second parameter is false the first function will be executed anyway.

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up vote 1 down vote

The second operand of a || or && will only be evaluated if the first operand doesn't already determine the result. See http://www.ecma-international.org/ecma-262/5.1/#sec-11.11.

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