ENV.each_key

ENV.each_key { |name| block } → ENV

ENV.each_key → an_enumerator

static VALUE
env_each_key(VALUE ehash)
{
    VALUE keys;
    long i;

    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    keys = env_keys(FALSE);
    for (i=0; i<RARRAY_LEN(keys); i++) {
        rb_yield(RARRAY_AREF(keys, i));
    }
    return ehash;
}

Yields each environment variable name:

Example

ENV.replace('foo' => '0', 'bar' => '1') # => ENV
names = []
ENV.each_key { |name| names.push(name) } # => ENV
names # => ["bar", "foo"]

Returns an Enumerator if no block given:

Example

e = ENV.each_key # => #<Enumerator: {"bar"=>"1", "foo"=>"0"}:each_key>
names = []
e.each { |name| names.push(name) } # => ENV
names # => ["bar", "foo"]

See also .each .each_pair .dup .each_value also in 4.1 · 4.0 · 3.3 · 3.2 · 3.1 · 3.0

‹ prev.each next ›.each_pair