PHP Data Types

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Variables can store data of different types, and different data types can do different things.

PHP supports the following data types:

  • String
  • Integer
  • Float (floating point numbers – also called double)
  • Boolean
  • Array
  • Object
  • NULL
  • Resource

PHP String

A string is a sequence of characters, like “Hello world!”.

A string can be any text inside quotes. You can use single or double quotes:

<?php
$dcs_first = "This is string with double quotes";
$dcs_second = "This is string with single quotes";
echo $dcs_first;
echo $dcs_second;
?>

Note: The output of above example will be two strings in one line. If you want these two lines in different line then use <br> HTML tag after first echo. Use the following example:

<?php
$dcs_first = "This is string with double quotes";
$dcs_second = "This is string with single quotes";
echo $dcs_first;
echo "<br>";
echo $dcs_second;
?>

PHP Integer

An integer is a whole number (without decimals).  It is a number between -2,147,483,648 and +2,147,483,647.

Rules for integers:

  • An integer must have at least one digit (0-9)
  • An integer cannot contain comma or blanks
  • An integer must not have a decimal point
  • An integer can be either positive or negative
  • Integers can be specified in three formats: decimal (10-based), hexadecimal (16-based – prefixed with 0x) or octal (8-based – prefixed with 0)

In the following example $x is an integer. The PHP var_dump() function returns the data type and value:

<?php 
$dcs_first_int = 9988;
echo "The value of integer is: ".$dcs_first_int;
?>

PHP Float

A float (floating point number) is a number with a decimal point or a number in exponential form.

In the following example $x is a float. The PHP var_dump() function returns the data type and value:

<?php 
$dcs_first_float = 99.88;
echo "The value of floating number is: ".$dcs_first_float;
?>

PHP Boolean

A Boolean represents two possible states: TRUE or FALSE.

<?php 
$dcs_true = true;
$dcs_false = false;
?>

PHP Array

An array stores multiple values in one single variable.

In the following example $cars is an array. The PHP var_dump() function returns the data type and value:

<?php 
$strs = array("string1","string2","string3","string4","string5");
print_r($strs);
?>

Note: The output of the above code will be totally deserted. For better formating, use <pre> HTML tag which will better format the output of the array. Use the following code:

<?php 
$strs = array("string1","string2","string3","string4","string5");
echo "<pre>";
print_r($strs);
echo "</pre>";
?>

PHP Object

An object is a data type which stores data and information on how to process that data.

In PHP, an object must be explicitly declared.

First we must declare a class of object. For this, we use the class keyword. A class is a structure that can contain properties and methods:

<?php
class dcs_obj {
     function dcs_obj() {
         $this->model = "techTutorialsOnline.com";
     }
}
// create an object
$dcs_variable = new dcs_obj();

// show object properties
echo "Site URL is :".$dcs_variable->model;
?>

This is all about PHP Data Types. If you have any question, you can ask it at Forum Section.