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+[[Property:uuid|C652AC71-8BAD-4387-A46C-21C9F5C3A68F]]
+[[Property:weight|0]]
+[[Property:title|Conditional expression]]
+[[Property:link_title|Conditional]]
+= Conditional expression =
+
+[[Eiffel%20Programming%20Language%20Syntax#Conditionals|Conditional expressions]] compute a value using different expressions depending on one or more conditions. If all expressions have the same type, the conditional expression as a whole has this type as well:
+
+<e>
+   if time < noon then
+      "Good morning"
+   elseif time < evening then
+      "Good afternoon"
+   else
+      "Good evening"
+   end
+</e>
+
+has type `STRING`.
+
+If the types of the expressions are different, the common ancestor type is used as a type of the whole expression.
+
+<e>
+   if time < noon then
+      "Good morning"
+   else
+      Void
+   end
+</e>
+
+has type `detachable STRING`.
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