Generally, the datatypes are used to hold different types of data (or) values. Datatypes specifies the different types of data that are supported in PHP.

PHP supports total eight primitive datatypes :

• Integer
• Float
• String
• Boolean
• Array
• Object
• NULL
• Resource

 Note :In PHP, var_dump() function returns the data type and value. Ex: int(123).

☞ Integer :

In PHP, Integers hold whole numbers including positive and negative numbers (... -3, -2, -1, 0, 1, 2, 3, ...). i.e., numbers without decimal point. They can be decimal (base 10), octal (0) or hexadecimal (0x) optionally preceded by + or - sign.

Example: "intdemo.php"

<?php

$var1 = 521; // decimal number

echo "Decimal Number is : ".$var1."<br>";

var_dump($var1);     // it prints datatype and value

echo "<br>";

 

$var2 = -675; // a negative number

echo "Negative Number is : ".$var2."<br>";

var_dump($var2);

echo "<br>";

 

$var3 = 0123; // octal number

echo "Octal Number is : ".$var3."<br>";

var_dump($var3);

echo "<br>";



$var4 = 0x1B; // hexadecimal number

echo "Hexadecimal Number is : ".$var4."<br>";

var_dump($var4);

?>

Output :

☞ Float :

A float (floating point number) is a number with a decimal point. It hold numbers containing fractional or decimal part including positive and negative numbers.

Example: "floatdemo.php"

<?php

$var1 = 23.45; // float

echo "Float Number is : ".$var1."<br>";

var_dump($var1);     // it prints datatype and value

echo "<br>";

 

$var2 = -67.12; // a negative float

echo "Negative Float Number is : ".$var2."<br>";

var_dump($var2);

echo "<br>";

 

$var3 = 10.2e3; // double 

echo "Double Number is : ".$var3."<br>";

var_dump($var3);

?>

Output :

☞ String :

A string is a sequence of characters which are enclosed with single quotes or double quotes.

Example: "stringdemo.php"

<?php

$var1 = "Hello PHP"; // string

echo "String is : ".$var1."<br>";

var_dump($var1);    // it prints datatype and value

echo "<br>";

 

$var2 = 'Study Glance'; // string

echo "String is : ".$var2."<br>";

var_dump($var2);

echo "<br>";

?>

Output :

☞ Boolean :

A boolean datatype hold two possible values either TRUE or FALSE.

Example: "blndemo.php"

<?php

$a= TRUE; // boolean

echo "Status is : ".$a."<br>";

var_dump($a);    // it prints datatype and value

echo "<br>";



$b= FALSE; // boolean

echo "Status is : ".$b."<br>";

var_dump($b);    // it prints datatype and value

?>

Output :

☞ Array :

An array datatype can hold more than one value at a time.In other words, An array is collection of elements or items.

Example: "arydemo.php"

<?php

$numbers = array(1,2,3,4,5);  //array

var_dump($numbers); // prints datatype and value

echo "<br>";

?>

Output :

☞ Object :

In PHP, Object is an instance of user defined class that can store both values and functions.Objects are created based on user defined class via the new keyword

Example: "objdemo.php"

<?php   

     class msg {  

          function display() {  

               $str = "Hello ! Welcome ";  

               echo $str;  

             }  

     }  

     $obj = new msg();  

     $obj -> display();  

     echo "<br>";

     var_dump($obj);

?>

Output :

☞ Null :

In PHP, Null is a special data type that has only one value: NULL, And it is case sensitive you must write in capital letters.The special type of data type NULL defined a variable with no value.

Example: "nulldemo.php"

<?php   

    $var = NULL;  

    echo $var;   //it will not give any output  

?>  

Output :

☞ Resource :

In PHP, A resource is a special variable, that hold a reference to an external resource such as database connection and opened files.The Resources are not exact data type in PHP

Example: "resdemo.php"

<?php

// Open a file for reading

$fp = fopen("file.txt", "r");

var_dump($fp);

echo "<br>";

echo $fp;

?>  

Output :

 Note : PHP supports eight primitive data types which are categorized into 3 main types. They are:

• Scalar Types: boolean, integer, float and string.
• Compound Types: array and object.
• Special Types: resource and NULL.