cond

performs conditional branching

For each pred-then clause, the predicate will be evaluated, and if it is truthy (not false), the then form is evaluated and returned, otherwise the next clause is processed.

An Example

(define x 99)

(cond
  [(< x 50)  "was less than 50"    ]
  [(> x 100) "was greater than 100"]
  [:else     "was in between"      ])

In this case, “was in between” will be returned. The reason that this works is that the :else keyword, like all keywords, evaluates to truthy.