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class method

ENV.merge!

ENV.update(hash) → ENV

ENV.update(hash) { |name, env_val, hash_val| block } → ENV

ENV.merge!(hash) → ENV

ENV.merge!(hash) { |name, env_val, hash_val| block } → ENV

static VALUE
env_update(VALUE env, VALUE hash)
{
    if (env == hash) return env;
    hash = to_hash(hash);
    rb_foreach_func *func = rb_block_given_p() ?
        env_update_block_i : env_update_i;
    rb_hash_foreach(hash, func, 0);
    return env;
}

ENV.update is an alias for ENV.merge!.

Adds to ENV each key/value pair in the given hash; returns ENV:

Example

ENV.replace('foo' => '0', 'bar' => '1')
ENV.merge!('baz' => '2', 'bat' => '3') # => {"bar"=>"1", "bat"=>"3", "baz"=>"2", "foo"=>"0"}

Deletes the ENV entry for a hash value that is nil:

Example

ENV.merge!('baz' => nil, 'bat' => nil) # => {"bar"=>"1", "foo"=>"0"}

For an already-existing name, if no block given, overwrites the ENV value:

Example

ENV.merge!('foo' => '4') # => {"bar"=>"1", "foo"=>"4"}

For an already-existing name, if block given, yields the name, its ENV value, and its hash value; the block’s return value becomes the new name:

Example

ENV.merge!('foo' => '5') { |name, env_val, hash_val | env_val + hash_val } # => {"bar"=>"1", "foo"=>"45"}

Raises an exception if a name or value is invalid (see Invalid Names and Values);

Example

ENV.replace('foo' => '0', 'bar' => '1')
ENV.merge!('foo' => '6', :bar => '7', 'baz' => '9') # Raises TypeError (no implicit conversion of Symbol into String)
ENV # => {"bar"=>"1", "foo"=>"6"}
ENV.merge!('foo' => '7', 'bar' => 8, 'baz' => '9') # Raises TypeError (no implicit conversion of Integer into String)
ENV # => {"bar"=>"1", "foo"=>"7"}

Raises an exception if the block returns an invalid name: (see Invalid Names and Values):

Example

ENV.merge!('bat' => '8', 'foo' => '9') { |name, env_val, hash_val | 10 } # Raises TypeError (no implicit conversion of Integer into String)
ENV # => {"bar"=>"1", "bat"=>"8", "foo"=>"7"}

Note that for the exceptions above, hash pairs preceding an invalid name or value are processed normally; those following are ignored.

See also .member? .rassoc .length .rehash also in 4.1 · 4.0 · 3.4 · 3.3 · 3.2 · 3.1

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