• PHP data types are used to hold different types of values or data.
• There are eight primitive data types which are further categorized into three types, they are:
  • Scalar types
  • Compound types
  • Special types

Scalar data types

• Scalar data types hold only single value and it consists of four data types, they are boolean, integer, float and string.

Boolean

• Booleans are the simplest data type works like switch and holds only two values TRUE (1) or FALSE (0).
• It is often used with conditional statements were if the condition is correct, it returns TRUE otherwise FALSE.

Sample Code

<?php   
    if (TRUE)  
        echo "This condition is TRUE.";  
    if (FALSE)  
        echo "This condition is FALSE.";  
?>  

Output

Integer

• Integer means numeric data, it can be either positive or negative sign.
• It holds only whole numbers, like numbers without decimal points or fractional parts.

Sample Code

<?php   
    $dec1 = 34;  
    $oct1 = 0243;  
    $hexa1 = 0x45;  
    echo "Decimal number: " .$dec1. "</br>";  
    echo "Octal number: " .$oct1. "</br>";  
    echo "HexaDecimal number: " .$hexa1. "</br>";  
?>  

Output

Float

• A floating-point number is a number with a decimal point and unlike integer, it can hold numbers with a fractional or decimal point, including a negative or positive sign.

Sample Code

<?php   
    $n1 = 19.34;  
    $n2 = 54.472;  
    $sum = $n1 + $n2;  
    echo "Addition of floating numbers: " .$sum;  
?>  

Output

String

• String is a non-numeric data type which holds letters or any alphabets, numbers, and even special characters.
• Its value must be enclosed either within single quotes or in double quotes and both are treated differently.

Sample  Code

<?php   
    $company = "Wikitechy";  
    //both single and double quote statements will treat different  
    echo "Welcome to $company";  
    echo "</br>";  
    echo "Welcome to $company';  
?>  

Output

Compound data type

• Compound data type can hold multiple and it consists of two data types, they are array and object.

Array

• In single variable an array canstore multiple values of same data type.

Sample Code

<?php   

    $bikes = array ("Royal Enfield", "Yamaha", "KTM");  

    var_dump($bikes);   //the var_dump() function returns the datatype and values 

    echo "</br>";  

    echo "Array Element1: $bikes[0] </br>";  

    echo "Array Element2: $bikes[1] </br>";  

    echo "Array Element3: $bikes[2] </br>";  

?>  

Output

Object

• Objects are the instances of user-defined classes that can store both functions and values.
• It must be explicitly declared.

Sample Code

<?php   
     class bike {  
          function model() {  
               $model_name = "Jawa";  
               echo "Bike Model: " .$model_name;  
             }  
     }  
     $obj = new bike();  
     $obj -> model();  
?>  

Output

Special Data Type

• Special data types consist of two types, they are Null and resource data type.

Null

• Null is a special data type that has only one value is NULL and there is a convention of writing it in capital letters as it is case sensitive.
• In special data type NULL defined a variable with no value.

Sample Code

<?php   
     $nl = NULL;  
    echo $nl;   //it will not give any output  
    ?>  

Output

Resource:

• In PHP resources are not the exact data type and basically these are used to references to external PHP resources or store some small function calls.