public static double ceil (double a)

Returns the smallest (closest to negative infinity)
` double`

value that is greater than or equal to the
argument and is equal to a mathematical integer. Special cases:

- If the argument value is already equal to a mathematical integer, then the result is the same as the argument.
- If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument.
- If the argument value is less than zero but greater than -1.0, then the result is negative zero.

` Math.ceil(x)`

is exactly the
value of ` -Math.floor(-x)`

.

`a` | a value. |

Diagram: Math