PHP Data Types

This tutorial helps you learn about the PHP data types. So, let's get started.

What Are the Data Types Supported By PHP?

The following basic data types are supported by PHP:

• Integer- It is used for whole numbers.
• Float (also called double)- It is used for real numbers
• String- It is used for strings of characters
• Boolean- It is used for true or false values
• Array- It is used for storing multiple data items
• Object- It is used to store instances of classes

Two special types of PHP Data are also available. These are:

• NULL
• Resource

PHP Integers Data Type

It is a non-decimal number between -2,147,483,648 and 2,147,483,647.

The rules for declaring integers data type:

• An integer must contain at least one digit (0-9)
• An integer cannot have commas or blanks.
• An integer should not have a decimal point.
• An integer can be positive or negative.
• You can specify integers in three formats: hexadecimal (16-based - prefixed with 0x), decimal (10-based), or octal (8-based - prefixed with 0)

Look at the example below to test different numbers.

The data type and value of variables are returned by the PHP var_dump() function:

<?php
    $x = 5186;      //positive number
    var_dump($x);
    echo "<br />";
    $x = -521;      //negative number
    var_dump($x);
    echo "<br />";
    $x = 0xF;       //hexadecimal number
    var_dump($x);
    echo "<br />";
    $x = 051;       //octal number
    var_dump($x);
?>

PHP Float Data Type

It is a number with either a decimal point or a number in exponential form.

In the example below, we will test different numbers.

<?php
    $x = 24.365;
    var_dump($x);
    echo "<br />";
    $x = 1.5e3;
    var_dump($x);
?>

PHP Strings Data Type

It is a sequence of characters, like "Hello world!".

It can be any text inside quotes. In addition, you can use single ' or " double quotes:

<?php
    $name = "Hello world!"; //double quote 
    echo $name;
    echo "<br />";
    $name = 'Hello world!'; //single quote
    echo $name;
?>

PHP Booleans Data Type

Booleans can be either TRUE or FALSE.

They are often used in conditional testing. In the later chapters of this tutorial, you will learn more about conditional testing.

<?php
    $x = true;
    $y = false;
?>

PHP Arrays

You can store multiple values in one single variable in an array. 

In the example given here, an array is created, and then the PHP var_dump() function is used to return the data type and value of the array:

In the later chapters of this tutorial, you will learn a lot more about arrays.

<?php
    $language = array("C","C++","JAVA");
    var_dump($language);
?>

PHP Objects

It is a data type that stores data and information on how to process that data. 

You must declare an object explicitly in PHP. 

First, a class of object must be declared. To do this, the class keyword is used. A class is a structure that can include properties and methods.

The data type is then defined in the object class, and then the data type is used in instances of that class:

In the later chapters of this tutorial, you will learn more about objects.

<?php
class Mobile {
  public $color;
  public $model;
  public function __construct($color, $model) {
    $this->color = $color;
    $this->model = $model;
  }
  public function message() {
    return "My mobile is a " . $this->color . " " . $this->model . "!";
  }
}

$myMobile = new Mobile("white", "Apple 13 Pro");
echo $myMobile -> message();
echo "<br>";
$myMobile = new Mobile("red", "Apple 13 Mini");
echo $myMobile -> message();
?>

PHP NULL Value

It represents that a variable has no value. Data type NUll's only possible is NULL. 

It identifies whether a variable is empty or not. Also helpful to distinguish between the empty string and null values of databases. 

You can empty the variables by setting the value to NULL:

<?php
    $var1 = "";    //empty string
    var_dump($var1);
    echo "<br />";
    $var2 = null;  //null value
    var_dump($var2);
?>

PHP Resource Value

Variables that have the type resource are returned by certain built-in functions (such as database functions). External Resources Value (such as database connections) is represented by them.

You will almost surely not directly manipulate a resource variable, but they are frequently returned by functions and must be passed as parameters to other functions.

<?php
    $con = mysqli_connect(host,username,password,dbname);
    /*here mysqli_connect() function returns Resource Value(database connection)*/
?>

In the above example, we store the connection in a variable ($con)