Maintenance Ruby 3.3 gets fixes, but no new features. Switch to Ruby 4.0 →
instance method
Array#to_h
array.to_h → new_hash
array.to_h {|item| ... } → new_hash
array.c
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static VALUE
rb_ary_to_h(VALUE ary)
{
long i;
VALUE hash = rb_hash_new_with_size(RARRAY_LEN(ary));
int block_given = rb_block_given_p();
for (i=0; i<RARRAY_LEN(ary); i++) {
const VALUE e = rb_ary_elt(ary, i);
const VALUE elt = block_given ? rb_yield_force_blockarg(e) : e;
const VALUE key_value_pair = rb_check_array_type(elt);
if (NIL_P(key_value_pair)) {
rb_raise(rb_eTypeError, "wrong element type %"PRIsVALUE" at %ld (expected array)",
rb_obj_class(elt), i);
}
if (RARRAY_LEN(key_value_pair) != 2) {
rb_raise(rb_eArgError, "wrong array length at %ld (expected 2, was %ld)",
i, RARRAY_LEN(key_value_pair));
}
rb_hash_aset(hash, RARRAY_AREF(key_value_pair, 0), RARRAY_AREF(key_value_pair, 1));
}
return hash;
}
Returns a new Hash formed from self.
When a block is given, calls the block with each array element; the block must return a 2-element Array whose two elements form a key-value pair in the returned Hash:
Example
a = ['foo', :bar, 1, [2, 3], {baz: 4}] h = a.to_h {|item| [item, item] } h # => {"foo"=>"foo", :bar=>:bar, 1=>1, [2, 3]=>[2, 3], {:baz=>4}=>{:baz=>4}}
When no block is given, self must be an Array of 2-element sub-arrays, each sub-array is formed into a key-value pair in the new Hash:
Example
[].to_h # => {} a = [['foo', 'zero'], ['bar', 'one'], ['baz', 'two']] h = a.to_h h # => {"foo"=>"zero", "bar"=>"one", "baz"=>"two"}