PHP provides three primitive data types: integers, floating point numbers, and strings. In addition, there are two compound data types: arrays and objects.
Integers are whole numbers. The range of integers in PHP is
equivalent to the range of the
long data type in
C. On 32-bit platforms, integer values can range from -2,147,483,648
to +2,147,483,647. PHP automatically converts larger values to
floating point numbers if you happen to overflow the range. An
integer can be expressed in decimal (base-10), hexadecimal (base-16),
or octal (base-8). For example:
$decimal=16; $hex=0x10; $octal=020;
Floating point numbers represent decimal values. The range of
floating point numbers in PHP is equivalent to the range of the
double type in C. On most platforms a double can
range from 1.7E-308 to 1.7E+308. A double may be expressed either as
a regular number with a decimal point or in scientific notation. For
Note that PHP also has a set of functions known as the BC (binary calculator) functions. These functions can manipulate arbitrary precision numbers. If you are dealing with very large numbers or numbers that require a high degree of precision, you should use these functions.
A string is a sequence of characters. A string can be delimited by single quotes or double quotes:
'PHP is cool' "Hello, World!"
Double-quoted strings are subject to variable substitution and escape sequence handling, while single quotes ...