Function array_replace

src/backend/utils/adt/arrayfuncs.c:6539–6558

* Replace any occurrences of an element in an array */

 * Replace any occurrences of an element in an array
 */
Datum
array_replace(PG_FUNCTION_ARGS)
{
	ArrayType  *array;
	Datum		search = PG_GETARG_DATUM(1);
	bool		search_isnull = PG_ARGISNULL(1);
	Datum		replace = PG_GETARG_DATUM(2);
	bool		replace_isnull = PG_ARGISNULL(2);

	if (PG_ARGISNULL(0))
		PG_RETURN_NULL();
	array = PG_GETARG_ARRAYTYPE_P(0);

	array = array_replace_internal(array,
								   search, search_isnull,
								   replace, replace_isnull,
								   false, PG_GET_COLLATION(),
								   fcinfo);
	PG_RETURN_ARRAYTYPE_P(array);
}

/*
 * Implements width_bucket(anyelement, anyarray).