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instance method

Hash#reject

hash.reject {|key, value| ... } → new_hash

hash.reject → new_enumerator

VALUE
rb_hash_reject(VALUE hash)
{
    VALUE result;

    RETURN_SIZED_ENUMERATOR(hash, 0, 0, hash_enum_size);
    if (RTEST(ruby_verbose)) {
        VALUE klass;
        if (HAS_EXTRA_STATES(hash, klass)) {
            rb_warn("extra states are no longer copied: %+"PRIsVALUE, hash);
        }
    }
    result = rb_hash_new();
    if (!RHASH_EMPTY_P(hash)) {
        rb_hash_foreach(hash, reject_i, result);
    }
    return result;
}

Returns a new Hash object whose entries are all those from self for which the block returns false or nil:

Example

h = {foo: 0, bar: 1, baz: 2}
h1 = h.reject {|key, value| key.start_with?('b') }
h1 # => {:foo=>0}

Returns a new Enumerator if no block given:

Example

h = {foo: 0, bar: 1, baz: 2}
e = h.reject # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:reject>
h1 = e.each {|key, value| key.start_with?('b') }
h1 # => {:foo=>0}

See also #reject! #rehash #rassoc #replace also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.1

‹ prev#rehash next ›#reject!