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_, ok := m[k]
k in m
array_key_exists($k, $m)
exists $m->{$k}
k in m
if (k in m) { }
m.containsKey(k)
m.include?(k)
Map.has_key?(m, k)
(/=Nothing) (lookup k m)
maps:is_key(K, M).
m[k] ~= nil
m.key?(k)
m.has_key?(k)
(assoc k m)
bool keyExists = m.ContainsKey(key)
m.contains(k)
m.hasOwnProperty(k)
m.containsKey(k)
(contains? m k)
_m.has(_k)
If m.ContainsKey(k) Then...
(nth-value 1 (gethash k m))
m includesKey: k.
M.Contains (K)