Ternary Operator - Please help me understand this line of code

Hello all,

I recently took over a project and I am trying to wrap my head around this line of code which uses the Ternary Operator. I am only familiar with the basics. I don’t quite understand the nested nature of this.

var s:String = ( index % 3 == 0 ) ? ( index == array.length-1 ) ? “Z” :“L” : " ";

Thanks in advance!

~squirt