Remove the backslash, add the "s" modifier. And the parens aren't necessary. 

my $cnt = @{[$str =~ /./sg]};

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Cheaper alternative: 

my $cnt =()= $str =~ /./sg;

[download]

In reply to Re^4: Counting number of characters in a string by ikegami
in thread Counting number of characters in a string by jeffpflueger

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