Summary: in this tutorial, you’ll learn about the PHP int type that represents integers in PHP.

Introduction to the PHP int type

Integers are whole numbers such as -3, -2, -1, 0, 1, 2, 3… PHP uses the int type to represent the integers.

The range of integers depends on the platform where PHP runs. Typically, integers has a range from -2,147,438,648 to 2,147,483,647. It’s equivalent to 32 bits signed.

To get the size of the integer, you use the PHP_INT_SIZE constant. Also, you use the PHP_INT_MIN and PHP_INT_MAX constants to get the minimum and maximum integer values.

PHP represents integer literals in decimal, octal, binary, and hexadecimal formats.

Decimal numbers

PHP uses a sequence of digits without leading zeros to represent decimal values. The sequence may begin with a plus or minus sign. If it has no sign, then the integer is positive. For example:

From PHP 7.4, you can use the underscores (_) to group digits in an integer to make it easier to read. For example, instead of using the following number:

you can use the underscores (_) to group digits like this:

Octal numbers

Octal numbers consist of a leading zero and a sequence of digits from 0 to 7. Like decimal numbers, the octal numbers can have a plus (+) or minus (-) sign. For example:

Code language: JavaScript (javascript)

Hexadecimal numbers

Hexadecimal numbers consist of a leading 0x and a sequence of digits (0-9) or letters (A-F). The letters can be lowercase or uppercase. By convention, letters are written in uppercase.

Similar to decimal numbers, hexadecimal numbers can include a sign, either plus (+) or minus(-). For example:

Code language: JSON / JSON with Comments (json)

Binary numbers

Binary numbers begin with 0b are followed by a sequence of digits 0 and 1. The binary numbers can include a sign. For example:

Code language: JavaScript (javascript)

The is_int() function

The is_int() built-in function returns true if a value (or a variable) is an integer. Otherwise, it returns false. For example:

Code language: PHP (php)

Output:

Summary

• Integers are whole numbers such as -1, 0, 1, 2…
• Use the PHP_INT_SIZE constant to get the size of the integer
• Use the PHP_INT_MIN and PHP_INT_MAX constants to get the minimum and maximum integer values.
• Literal integers can be in decimal, octal, hexadecimal, and binary forms.
• Use the is_int() function returns true if a value (or variable) is an integer.