An array of arguments:

• [0] – The numeric value to round.
• [1] – The number of decimal places.
• [2] (optional) – The rounding mode. If omitted or unknown, the default mode is used.

Nearest modes (round to the nearest value; differ only on exact ties):

• "banker", "toeven", "halfeven" (default) – Rounds ties to the nearest even value (HALF_EVEN).
• "halfup", "awayfromzero" – Rounds ties away from zero (HALF_UP).
• "halfdown" – Rounds ties toward zero (HALF_DOWN).

Directed modes (always round in a fixed direction):

• "up" – Rounds away from zero for all values (UP). Note: this is not the same as "halfup".
• "down", "truncate", "tozero" – Rounds toward zero (DOWN).
• "ceiling", "ceil" – Rounds toward positive infinity (CEILING).
• "floor" – Rounds toward negative infinity (FLOOR).