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2013-05-17T18:13:47Z

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== Variables and Datatypes ==

A variable is a keyword or phrase that acts as an identifier for a value stored in a system’s memory.

'''Storing Values in a Variable'''
PHP lets you store nearly anything in a variable using one of the following datatypes:
String: Alphanumeric characters
Integer: A numeric value, expressed in whole numbers
Float: A numeric value, expressed in real numbers (decimals)
Boolean: Evaluates to TRUE or FALSE
Array: An indexed collection of data
Object: A collection of data and methods

PHP is a loosely typed language, which means it determines the type of data being handled based on a “best guess” principle, as opposed to a strictly typed language such as C, which requires you name datatypes for every variable and function. Consider this code snippet:
$foo = "5"; // This is considered a string
$bar = $foo + 2; // This converts $foo to an integer (outputs 7)

This might seem confusing at first, but it’s actually intuitive and eliminates debugging if you
enclose a number in quotes accidentally.

== Strings ==

A string is any series of characters enclosed in single (') or double (") quotes, or that you create using
special heredoc or nowdoc syntax,

'''Single-Quote Syntax'''

doesn’t expand special characters or variables.
A backslash doesn't need to be escaped to print it as a regular character.

'''Double-Quote Syntax '''

special characters interpreted & variables are expanded (unless escaped)

'''String Concatenation'''
done with a period (.)
$foo = "This is a " . "string.";

$foo = "This is a ";
$bar = "string.";

both produce
echo $foo . $bar;
This is a string.

PHP is a loosely typed language, it’s not necessary to declare a variable as an integer

'''Heredoc and Nowdoc syntax'''
skipped...

== Integers ==
Because PHP is a loosely typed language, it’s not necessary to declare a variable as an integer;
however, if you find it necessary, you can explicitly cast, or force, a value as an integer using the
following syntax:
$foo = 27; // No quotes around a whole number always means integer
$bar = (int) "3-peat" // Evaluates to 3, evaluates the numeric value if at the beginning of the string
$bat = (int) "ten 4"; // Evaluates to 0, because the string doesn't start with a numeric value

'''Floating point numbers''' are numbers with decimal values or real numbers. They should not be used in equality comparisons.

A '''Boolean''' value is can contain only one of two values: TRUE or FALSE.

Note A string value will always evaluate to 0 unless it starts with a numeric value (such as “10 years”).

== Tips ==

Browsers don't interpret newline characters (\n), but php can.

[[category:php]]

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