Assaph Mehr
5/19/2005 12:01:00 AM
Boris Glawe wrote:
> Hi,
>
> my problem is obviously very basic, but how to I acces for example
the third
> character of the string "hello" ??
>
> The [] method does not behave as expected, the each method returns
the whole
> string, the methods of Enumerable mixin don't help me...
>
> This can't be that hard to solve!?
>
> thanks Boris
Just convert the Fixnum into a character:
irb(main):005:0> s = 'hello'
=> "hello"
irb(main):006:0> s[2]
=> 108
irb(main):007:0> s[2].chr
=> "l"
>From the docs:
--------------------------------------------------------------
String#[]
str[fixnum] => fixnum or nil
str[fixnum, fixnum] => new_str or nil
str[range] => new_str or nil
str[regexp] => new_str or nil
str[regexp, fixnum] => new_str or nil
str[other_str] => new_str or nil
str.slice(fixnum) => fixnum or nil
str.slice(fixnum, fixnum) => new_str or nil
str.slice(range) => new_str or nil
str.slice(regexp) => new_str or nil
str.slice(regexp, fixnum) => new_str or nil
str.slice(other_str) => new_str or nil
------------------------------------------------------------------------
Element Reference---If passed a single +Fixnum+, returns the code
of the character at that position. If passed two +Fixnum+ objects,
returns a substring starting at the offset given by the first, and
a length given by the second. If given a range, a substring
containing characters at offsets given by the range is returned.
In
all three cases, if an offset is negative, it is counted from the
end of _str_. Returns +nil+ if the initial offset falls outside
the
string, the length is negative, or the beginning of the range is
greater than the end.
If a +Regexp+ is supplied, the matching portion of _str_ is
returned. If a numeric parameter follows the regular expression,
that component of the +MatchData+ is returned instead. If a
+String+ is given, that string is returned if it occurs in _str_.
In both cases, +nil+ is returned if there is no match.
a = "hello there"
a[1] #=> 101
a[1,3] #=> "ell"
a[1..3] #=> "ell"
a[-3,2] #=> "er"
a[-4..-2] #=> "her"
a[12..-1] #=> nil
a[-2..-4] #=> ""
a[/[aeiou](.)\1/] #=> "ell"
a[/[aeiou](.)\1/, 0] #=> "ell"
a[/[aeiou](.)\1/, 1] #=> "l"
a[/[aeiou](.)\1/, 2] #=> nil
a["lo"] #=> "lo"
a["bye"] #=> nil