The main way to store information in the middle of a PHP program is by using a variable.
- Here are the most important things to know about variables in PHP.
- All variables in PHP are denoted with a leading dollar sign ($).
- The value of a variable is the value of its most recent assignment.
- Variables are assigned with the = operator, with the variable on the left-hand side and
- the expression to be evaluated on the right.
- Variables can, but do not need, to be declared before assignment.
- Variables in PHP do not have intrinsic types - a variable does not know in advance
- whether it will be used to store a number or a string of characters.
- Variables used before they are assigned have default values.
PHP does a good job of automatically converting types from one to another when
necessary.
PHP variables are Perl-lik
PHP has a total of eight data types which we use to construct our variables:Integers: are whole numbers, without a decimal point, like 4195.
Doubles: are floating-point numbers, like 3.14159 or 49.1.
Booleans: have only two possible values either true or false.
NULL: is a special type that only has one value: NULL.
Strings: are sequences of characters, like 'PHP supports string operations.'
Arrays: are named and indexed collections of other values.
Objects: are instances of programmer-defined classes, which can package up both other kinds of values and functions that are specific to the class.
Resources: are special variables that hold references to resources external to PHP
(such as database connections).
The first five are simple types, and the next two (arrays and objects) are compound - the
compound types can package up other arbitrary values of arbitrary type, whereas simple
types cannot.
Here's My PHP code
<?php
$x = 4;
function assignx () {$x = 0;
print "\$x inside function is $x.
";
}
assignx();
print "\$x outside of function is $x.
";
?>
This will produce the following result.
<?php
$x inside function is 0.
$x outside of a function is 4.
?>
Top comments (0)