Method: Enumerable#minmax_by

Defined in:
enum.c

#minmax_by {|element| ... } ⇒ Array #minmax_by ⇒ Object

Returns a 2-element array containing the elements for which the block returns minimum and maximum values:

(1..4).minmax_by {|element| -element }
# => [4, 1]
%w[a b c d].minmax_by {|element| -element.ord }
# => ["d", "a"]
{foo: 0, bar: 1, baz: 2}.minmax_by {|key, value| -value }
# => [[:baz, 2], [:foo, 0]]
[].minmax_by {|element| -element }
# => [nil, nil]

Returns an Enumerator if no block is given.

Related: #max_by, #minmax, #min_by.

Overloads:

  • #minmax_by {|element| ... } ⇒ Array

    Yields:

    • (element)

    Returns:



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# File 'enum.c', line 2927

static VALUE
enum_minmax_by(VALUE obj)
{
    VALUE memo;
    struct minmax_by_t *m = NEW_MEMO_FOR(struct minmax_by_t, memo);

    RETURN_SIZED_ENUMERATOR(obj, 0, 0, enum_size);

    m->min_bv = Qundef;
    m->max_bv = Qundef;
    m->min = Qnil;
    m->max = Qnil;
    m->last_bv = Qundef;
    m->last = Qundef;
    rb_block_call(obj, id_each, 0, 0, minmax_by_i, memo);
    if (!UNDEF_P(m->last_bv))
        minmax_by_i_update(m->last_bv, m->last_bv, m->last, m->last, m);
    m = MEMO_FOR(struct minmax_by_t, memo);
    return rb_assoc_new(m->min, m->max);
}