Finding the number of boxes that fit into a truck using JavaScript (Followup Q)
This is an interesting pattern:

var heightA = boxHeight &gt; 0 ? ((truckHeight / boxHeight) | 0) : 0;


I assume you intend to be using integer division here? Ie, 5/2 | 0 = 2? 

Also.. why are you repeatedly declaring different variables with the same values? 

var heightA = boxHeight &gt; 0 ? ((truckHeight / boxHeight) | 0) : 0;
var heightB = boxHeight &gt; 0 ? ((truckHeight / boxHeight) | 0) : 0;
var heightC = boxHeight &gt; 0 ? ((truckWidth / boxHeight) | 0) : 0;


Here you are comparing two fundamentally different types: 

if (multiplesA &gt; arrayA)
{
boxCount = multiplesA;
}


Comparing different data types in Javascript involves the type coercion system, which in javascript is a Bad Thing -- you're basically putting yourself at the mercy of an extremely unpredictable system. But, beyond that, it's not even clear what your intention with this line is -- how does it make sense to compare a float to an array?