Comments and constructs
Use comments to add descriptions to your expressions. This is especially useful when maintaining large and complex expressions.
<expression1> // this is a comment <expression2>
Use the if-then-else construct to create conditional expressions. The conditional expression can be nested, or used as part of another expression.
if <logical expression> then <expression1> else <expression2>
The logical expression must evaluate to true or false. If the logical expression is true, expression1 is evaluated and is used as the result of the expression. If the logical expression is false, expression2 is evaluated and used as the result.