Ternary Conditional

The ternary operator evaluates a condition and returns one of two values. It is right-associative.

condition ? trueExpression : falseExpression

var status = Data.active ? "on" : "off"

Nesting

Ternary expressions can be nested for multi-way selection:

var grade = score >= 90 ? "A" : score >= 80 ? "B" : "C"

Right-associativity means the above is parsed as:

var grade = score >= 90 ? "A" : (score >= 80 ? "B" : "C")

Short-circuit evaluation

The ternary operator only evaluates the branch that is selected by the condition. The other branch is skipped entirely, so it is safe to put expressions that would otherwise fail in the guarded branch:

var result = count > 0 ? total / count : 0    # No division-by-zero risk