Hi ankitpati, 

map { $_ => 1 } @_

[download]
returns list having even number of elements. 'keys' works only on hashes. In your working example %hash is initialized with the list returned by 'map' and then 'keys' can do the job on %hash.

HTH

In reply to Re: Why does 'keys' need a named hash? by pme
in thread Why does ‘keys’ need a named hash? by ankitpati

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