Variables are capable of storing many types of data.
PHP supports all the typical types of data types that other programming languages support. These data types include: Integer Float (floating-point numbers — also known as double) String Boolean Array Object NULL Resource
PHP Integer A PHP integer is any non-decimal number between -2,147,483,648 and 2,147,483,647. Some of the rules that integers must follow are: -An integer must have one or more digits -There must be no digits after the invisible decimal -An integer may be either positive or negative <?php $a = 123; echo $a; ?>
Result
PHP Float
A float is any positive or negative number. Unlike integers, you can have digits after the decimal point.
Example
<?php
$a = 123.123;
echo $a;
?>
Result
PHP String
A string is any sequence of letters such as “Hi, how are you”. The entire text inside of the quotation is considered a string.
<?php $a = "word"; echo $a; ?>
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PHP Boolean This means the value can only be either TRUE or FALSE <?php $a = TRUE; echo $a; ?>
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Some Other Variable Types Some other types of commonly used variables include arrays, objects, NULL and resources.
*PHP Array An array means you are storing more than one values in the variable. Arrays are explained in more detail here.
PHP Object
An object is an instance of a class. An object can do two purposes: it can store data(often multiple values) and it can also process data in different way. To use an object, you must explicitly declare it. You must also have a particular class already created.
/***You can learn more about PHP classes here ***/
Example
class Person {
public $name;
function __construct($name) {
$this->name = $name;
}
function get_name() {
echo $this->name;
}
}
$person = new Person("John Smith");
$person->get_name();
?>
Result
In addition, a variable can also be null or a resource. PHP NULL
Null
is a special type of data that can only have the value of NULL.
By default, any variable that is not set has a value of NULL.
You are free to set any variable’s value to NULL in order to get rid of it.
Any variable that hasn’t been created also has a type and value of NULL.
PHP Resource
A resource is something returned by a built-in function. For example, a database connection or a file connection or a directory. Each resource has its own unique behaviour and is better understood individually. Resources are considered an advanced topic, so it is better you come back to this topic at a later time.