By the way, may I know that is there any function like e.g.
left(line,
3), right(line, 2) and mid(line, 1, 4) to extract letter from a line,
please?
e.g.
mid(gghhii,3,2) return hh
left(gghhii,3) return ggh
right(gghhii,3) return hii
Remember that arrays and strings start at index 0, not index 1.
str = "gghhii"
p str[ 0, 3 ] #=> "ggh"
p str[ -3, 3 ] #=> "hii"
p str[ 2, 2 ] #=> "hh"
class String
def left( chars )
self[ 0, chars ]
end
def right( chars )
self[ -chars, chars ]
end
def mid( start, chars )
self[ start, chars ]
end
end
p str.left( 3 ) #=> "ggh"
p str.right( 3 ) #=> "hii"
p str.mid( 2, 2 ) #=> "hh"
For more ways to manipulate strings, please type "ri String" into your
prompt.