# As in Perl to round a number to the nearest integer in a big way

Task. In Perl, the program has a variable which is a number. You need to round it to the nearest whole in a big way.

Here are some examples of values. All these numbers must be converted to number `11`:

• `10.001`
• `10.4`
• `10.5`
• `10.99`
• `11`

## The solution is to use the function `ceil`

The best way to solve this problem is to use the function `ceil` from the library `POSIX`.

Library `POSIX` comes with Perl, so if you have Perl, this library is available to additionally install nothing.

Here is a sample program:

▶ Run
``````#!/usr/bin/perl

use POSIX;

my \$number = 10.3;

print ceil(\$number);
``````

The program will display the number 11.

• `use POSIX;` — connected the library `POSIX`. As soon as we connected this library, we immediately became available a few functions that are defined in this library.
• `my \$number = 10.3;` — create a variable `\$number` and put the number `10.3`.
• `print ceil(\$number);` — Used function `ceil` and display the result of its work.

Function `ceil` (in English this word is translated as "ceiling") is fairly standard. In many programming languages there is a function with the same name and which works exactly the same.

In addition to the functions `ceil` there is still a function of `floor` ("gender"), which rounds a number to the nearest integer. Ie in the case of non-negative numbers just cuts off the entire fractional part.

## In case of negative numbers

Function `ceil` for negative numbers works the same way as for positive numbers — rounds the number to the nearest integer in a big way.

In the case of negative numbers, it means that the function will simply cut off the entire fractional part.

All of these numbers when using `ceil` will become the number `-5`:

• `-5`
• `-5.1`
• `-5.5`
• `-5.9`