I get that this:
return A ? B : C
means
If A is true, return B, else return C
But how do I read this one:
return A ? B ? C : D : E
Not my code; I just need to understand it.
I've seen this answer/solution, but just saying "Javascript is right-associative, so you 'resolve' the ternaries from right to left" doesn't seem to answer the question.
To clarify, A ? B : C is a ternary operator. Instead of A, B, and C, we can rewrite it as:
BOOLEAN ? EXPRESSION 1 : EXPRESSION 2
Depending on if BOOLEAN is either TRUE or FALSE, we will return EXPRESSION 1 or EXPRESSION 2.
A ? B ? C : D : E is a Nested Ternary. We basically have this:
BOOLEAN 1 ? (BOOLEAN 2 ? EXPRESSION 1 : EXPRESSION 2) : EXPRESSION 3
EXPRESSION 1 from our previous example is now (BOOLEAN 2 ? EXPRESSION 1 : EXPRESSION 2)
So, reading it:
When BOOLEAN 1 is TRUE, we return the nested ternary operator, and do a second evaluation (BOOLEAN 2 TRUE? return EXPRESSION 1, otherwise return EXPRESSION 2). However, if BOOLEAN 1 is FALSE, we return EXPRESSION 3