[] -> 0 (type string)
[5apple] -> 5 (type string)
[NaN] -> 0 (type string)
[-NaN] -> nan (type strnum)
[+NaN] -> nan (type strnum)
[ 6] -> 6 (type strnum)
[0x1az] -> 26 (type string)
[011Q] -> 9 (type string)
[027] -> 23 (type strnum)