=over =item length EXPR X X =item length Returns the length in I of the value of EXPR. If EXPR is omitted, returns the length of L|perlvar/$_>. If EXPR is undefined, returns L|/undef EXPR>. This function cannot be used on an entire array or hash to find out how many elements these have. For that, use C and C, respectively. Like all Perl character operations, L|/length EXPR> normally deals in logical characters, not physical bytes. For how many bytes a string encoded as UTF-8 would take up, use C (you'll have to C first). See L and L. =back