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class method

ENV.keep_if

ENV.keep_if {|name, value| ... } → ENV

ENV.keep_if → an_enumerator

static VALUE
env_keep_if(VALUE ehash)
{
    RETURN_SIZED_ENUMERATOR(ehash, 0, 0, rb_env_size);
    env_select_bang(ehash);
    return envtbl;
}

Calls the block with each environment variable name and value, deleting each environment variable for which the block returns false or nil, and returning ENV:

Example

ENV.replace('foo' => '0', 'bar' => '1', 'baz' => '2')
ENV.keep_if { |name, value| name.start_with?('b') } # => ENV
ENV # => {"bar"=>"1", "baz"=>"2"}

With no block given, returns a new Enumerator.

See also .invert .key .inspect .key? also in 4.0 · 3.4 · 3.3 · 3.2 · 3.1 · 3.0

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