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Hash#update
static VALUE
rb_hash_update(int argc, VALUE *argv, VALUE self)
{
int i;
bool block_given = rb_block_given_p();
rb_hash_modify(self);
for (i = 0; i < argc; i++){
VALUE hash = to_hash(argv[i]);
if (block_given) {
rb_hash_foreach(hash, rb_hash_update_block_i, self);
}
else {
rb_hash_foreach(hash, rb_hash_update_i, self);
}
}
return self;
}
Merges each of other_hashes into self; returns self.
Each argument in other_hashes must be a Hash.
Method update is an alias for #merge!.
With arguments and no block:
-
Returns
self, after the given hashes are merged into it. -
The given hashes are merged left to right.
-
Each new entry is added at the end.
-
Each duplicate-key entry’s value overwrites the previous value.
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h.merge!(h1, h2) # => {:foo=>0, :bar=>4, :baz=>2, :bat=>6, :bam=>5}
With arguments and a block:
-
Returns
self, after the given hashes are merged. -
The given hashes are merged left to right.
-
Each new-key entry is added at the end.
-
For each duplicate key:
-
Calls the block with the key and the old and new values.
-
The block’s return value becomes the new value for the entry.
-
Example:
h = {foo: 0, bar: 1, baz: 2} h1 = {bat: 3, bar: 4} h2 = {bam: 5, bat:6} h3 = h.merge!(h1, h2) { |key, old_value, new_value| old_value + new_value } h3 # => {:foo=>0, :bar=>5, :baz=>2, :bat=>9, :bam=>5}
With no arguments:
-
Returns
self, unmodified. -
The block, if given, is ignored.
Example:
h = {foo: 0, bar: 1, baz: 2} h.merge # => {:foo=>0, :bar=>1, :baz=>2} h1 = h.merge! { |key, old_value, new_value| raise 'Cannot happen' } h1 # => {:foo=>0, :bar=>1, :baz=>2}