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Task/Undefined-values/Sidef/undefined-values.sidef

@@ -0,0 +1,13 @@
+var x;      # declared, but not defined
+x == nil   && say "nil value";
+defined(x) || say "undefined";
+
+# Give "x" some value
+x = 42;
+
+defined(x) && say "defined";
+
+# Change "x" back to `nil`
+x = nil;
+
+defined(x) || say "undefined";