Skip to main content

PHP - Integers

In PHP, an integer (int) is a built-in scalar data type representing whole numbers without decimal points. Integers can be represented in decimal (base 10), hexadecimal (base 16), octal (base 8), or binary (base 2) notation.

Integer Notation Examples​

Example:

$a = 1234;
echo "1234 is an Integer in decimal notation: $a\n";

$b = 0123; 
echo "0o123 is an integer in Octal notation: $b\n";

$c = 0x1A; 
echo "0xaA is an integer in Hexadecimal notation: $c\n";

$d = 0b1111;
echo "0b1111 is an integer in binary notation: $d";

Output:

1234 is an Integer in decimal notation: 1234
0o123 is an integer in Octal notation: 83
0xaA is an integer in Hexadecimal notation: 26
0b1111 is an integer in binary notation: 15

Underscore Separator in Integer Literals​

From PHP 7.4.0 onwards, integer literals may contain underscores (_) as separators between digits for better readability.

Example:

$a = 1_234_567; 
echo "1_234_567 is an Integer with _ as separator: $a";

Output:

1_234_567 is an Integer with _ as separator: 1234567

Integer Size and Range​

PHP does not support unsigned integers. The size of an int is platform-dependent. On 32-bit systems, the maximum value is about two billion. 64-bit platforms usually have a maximum value of about 9E18.

Constants like PHP_INT_SIZE, PHP_INT_MAX, and PHP_INT_MIN provide information about integer size, maximum, and minimum values.

Integer Division​

PHP doesn't have a specific operator for integer division. Division between an integer and a float always results in a float. To obtain integral division, use intval() or intdiv().

Example:

$x = 10;
$y = 3.5;
$z = $x / $y;
var_dump($z);  // float(2.857142857142857)

$z = intdiv($x, $y);
var_dump($z);  // int(3)

Mermaid Diagram​

This diagram illustrates different aspects of integers in PHP, including notation examples, underscore separator usage, size and range, and integer division.