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Null object: Difference between revisions
→{{header|Clojure}}
(Fixing an error in Objective-C semantics) |
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Line 144:
<lang lisp>(let [x nil]
(println "Object is" (if (nil? x) "nil" "not nil")))</lang>
Test wether symbol <code>foo</code> is defined:
<lang lisp>(find (ns-interns *ns*) 'foo)</lang>
Undefining <code>foo</code>:
<lang lisp>(ns-unmap *ns* 'foo)</lang>
=={{header|Common Lisp}}==
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