Conditional expressions
JSONiq follows the W3C standard for conditional expressions. The following explanations, provided as an informal summary for convenience, are non-normative.
Figure 49. IfExpr
A conditional expressions allows you to pick one or another value depending on a boolean value.
Example 97. A conditional expression
if (1 + 1 eq 2) then { "foo" : "yes" } else { "foo" : "false" }
Result (run with Zorba): { "foo" : "yes" }
The behavior of the expression inside the if is similar to that of logical operations (two-valued logics), meaning that non-boolean values get converted to a boolean.
Example 98. A conditional expression
if (null) then { "foo" : "yes" } else { "foo" : "no" }
Result (run with Zorba): { "foo" : "no" }
Example 99. A conditional expression
if (1) then { "foo" : "yes" } else { "foo" : "no" }
Result (run with Zorba): { "foo" : "yes" }
Example 100. A conditional expression
if (0) then { "foo" : "yes" } else { "foo" : "no" }
Result (run with Zorba): { "foo" : "no" }
Example 101. A conditional expression
if ("foo") then { "foo" : "yes" } else { "foo" : "no" }
Result (run with Zorba): { "foo" : "yes" }
Example 102. A conditional expression
if ("") then { "foo" : "yes" } else { "foo" : "no" }
Result (run with Zorba): { "foo" : "no" }
Example 103. A conditional expression
if (()) then { "foo" : "yes" } else { "foo" : "no" }
Result (run with Zorba): { "foo" : "no" }
Example 104. A conditional expression
if (({ "foo" : "bar" }, [ 1, 2, 3, 4])) then { "foo" : "yes" } else { "foo" : "no" }
Result (run with Zorba): { "foo" : "yes" }
Note that the else clause is mandatory (but can be the empty sequence)
Example 105. A conditional expression
if (1+1 eq 2) then { "foo" : "yes" } else ()
Result (run with Zorba): { "foo" : "yes" }