Eight different data types exist in PHP, five of which are scalar and each of the remaining three has its own uniqueness. The previously discussed variables can contain values of any of these data types without explicitly declaring their type. The variable “behaves” according to the data type it contains.
Integers are whole numbers and are equivalent in range as your C compiler's long value. On many common machines, such as Intel Pentiums, that means a 32-bit signed integer with a range between –2,147,483,648 to +2,147,483,647.
Integers can be written in decimal, hexadecimal (prefixed with 0x), and octal notation (prefixed with 0), and can include +/- signs.
Some examples of integers include
240000 0xABCD ...