DB<8> x ["a",=>"b"]
0  ARRAY(0x54e32f0)
   0  'a'
   1  'b'
  DB<9> x ["a",,"b"]
0  ARRAY(0x54e2cd8)
   0  'a'
   1  'b'

##</code><code>##

  DB<12> x map {lc,$_} "A".."C"
0  'a'
1  'A'
2  'b'
3  'B'
4  'c'
5  'C'