A number is a mathematical object and one of the datatypes which is used to count, measure and calculation. In computer programming, a number is very important datatype. PHP has two types of numbers, Integers & Floating point numbers. PHP allows us to perform different PHP Number Manipulation operations on numbers for example comparing numbers, operation on series etc.

Using PHP's built in function is_int() and is_double(), it is possible to check whether variable is a number.

<?php $num = '130.12'; if(in_int($num) || in_double($num)) echo '$num is a number'; ?>

**This will produce following result**

$num is a number

Using PHP's built in function gettype(), it is possible to check whether variable is a number by getting its type.

<?php $num = '130.12'; if(gettype($num) == 'integer' || gettype($num) == 'double') echo '$num is a number'; ?>

**This will produce following result**

$num is a number

Using PHP's built in function round(), it is possible to round off floating point number through round() function.

<?php $x = round(13.30); echo $x; ?>

**This will produce following result**

13

Using PHP's built in function abs(), it is possible to compare two approximately equal floating point numbers through abs() function.

<?php $x = 25.0000001; $y = 25.0000000; if(abs($x-$y)<0.00001){ echo "$x and $y are approximately equal."; ?>

**This will produce following result**

25.0000001 and 25.0000000 are approximately equal.

Using PHP's built in function abs(), it is possible to apply a single code to a range of integers using loops.

<?php $x = 2; $y = 8; echo "List of even numbers between 2 and 8 is:" for ($z = $x; $z <= $y; $z++){ echo $z/n; ?>

**This will produce following result**

List of even numbers between 2 and 8 is: 2 4 6 8

Using PHP's built in function sort(), it is possible to search for the number having minimum value in an array of unordered numbers.

<?php $x = array(100,1,50,25,10); $y = sort($x); echo "Minimum value in the array is $y[0]."; ?>

**This will produce following result**

Minimum value in the array is 1.

Using PHP's built in function sort(), it is possible to search for the number having maximum value in an array of unordered numbers.

<?php $x = array(100,1,50,25,10); $y = sort($x); echo "Maximum value in the array is $y[sizeof($y)-1]."; ?>

**This will produce following result**

Maximum value in the array is 100.

Using PHP's built in function decbin() and bindec(), it is possible to convert a number into binary and decimal.

<?php $num = 433; $binary = decbin($num); $decimal = bindec($binary); ?>

Using PHP's built in function octdec() and hexdec(), it is possible to convert a number into octal and hexadecimal.

<?php $num = 433; $binary = octdec($num); $decimal = hexdec($binary); ?>

Using PHP's built in function number_format(), it is possible to output a number with commas in the correct places.

<?php $num = 4330887.765; echo number_format($num,2); ?>