Preview Ruby 4.1 is a preview. It can change before the final release. Switch to Ruby 4.0 →

instance method · added in Ruby 3.2

MatchData#byteoffset

(::MatchData::capture backref) -> ([ ::Integer, ::Integer ] | [ nil, nil ])

mtch.byteoffset(n) → array

static VALUE
match_byteoffset(VALUE match, VALUE n)
{
    int i = match_backref_number(match, n);

    match_check(match);
    backref_number_check(match, i);

    if (RMATCH_BEG(match, i) < 0)
        return rb_assoc_new(Qnil, Qnil);
    return rb_assoc_new(LEN2NUM(RMATCH_BEG(match, i)), LEN2NUM(RMATCH_END(match, i)));
}

Returns a two-element array containing the beginning and ending byte-based offsets of the nth match. n can be a string or symbol to reference a named capture.

Example

m = /(.)(.)(\d+)(\d)/.match("THX1138.")
m.byteoffset(0)      #=> [1, 7]
m.byteoffset(4)      #=> [6, 7]

m = /(?<foo>.)(.)(?<bar>.)/.match("hoge")
p m.byteoffset(:foo) #=> [0, 1]
p m.byteoffset(:bar) #=> [2, 3]

Ruby version changes

3.2
- MatchData#byteoffset has been added. [Feature #13110]

See also #byteend #captures #bytebegin #deconstruct also in 4.0 · 3.4 · 3.3 · 3.2

‹ prev#byteend next ›#captures