Data Types:

HP data types are used to hold different types of data or values. PHP supports 8 primitive data types that can be categorized further in 3 types:

• Scalar Types (predefined)
• Compound Types (user-defined)
• Special Types

It holds only single value. There are 4 scalar data types in PHP.

• boolean
• integer
• float
• string

It can hold multiple values. There are 2 compound data types in PHP.

• array
• object

There are 2 special data types in PHP.

• resource
• NULL

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

    if (TRUE)  
        echo "This condition is TRUE.";  
    if (FALSE)  
        echo "This condition is FALSE.";  
		
		
	output:This condition is TRUE.
 

Integer means numeric data with a negative or positive sign. It holds only whole numbers, i.e., numbers without fractional part or decimal points.s

• An integer can be either positive or negative.
• An integer must not contain decimal point.
• Integer can be decimal (base 10), octal (base 8), or hexadecimal (base 16).
• The range of an integer must be lie between 2,147,483,648 and 2,147,483,647 i.e., -2^31 to 2^31.

    $dec1 = 34;  
    $oct1 = 0243;  
    $hexa1 = 0x45;  
    echo "Decimal number: " .$dec1. "
";  
    echo "Octal number: " .$oct1. "
";  
    echo "HexaDecimal number: " .$hexa1. "
";  
		
		
	output:
	Decimal number: 34
	Octal number: 163
	HexaDecimal number: 69
 

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

    $n1 = 19.34;  
    $n2 = 54.472;  
    $sum = $n1 + $n2;  
    echo "Addition of floating numbers: " .$sum;  
		
	output:Addition of floating numbers: 73.812
 

A string is a non-numeric data type. It holds letters or any alphabets, numbers, and even special characters.

String values must be enclosed either within single quotes or in double quotes. But both are treated differently. To clarify this, see the example below:

    $company = "Javatpoint";  
    //both single and double quote statements will treat different  
    echo "Hello $company";  
    echo "
";  
    echo 'Hello $company';  
		
	output:
	Hello Javatpoint
    Hello $company
 

An array is a compound data type. It can store multiple values of same data type in a single variable.

     $bikes = array ("Royal Enfield", "Yamaha", "KTM");  
    var_dump($bikes);   //the var_dump() function returns the datatype and values  
    echo "
";  
    echo "Array Element1: $bikes[0] 
";  
    echo "Array Element2: $bikes[1] 
";  
    echo "Array Element3: $bikes[2] 
";  
		
	output:
	array(3) { [0]=> string(13) "Royal Enfield" [1]=> string(6) "Yamaha" [2]=> string(3) "KTM" }
	Array Element1: Royal Enfield
	Array Element2: Yamaha
	Array Element3: KTM
 

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

Resources are not the exact data type in PHP. Basically, these are used to store some function calls or references to external PHP resources. For example - a database call. It is an external resource.

Null is a special data type that has only one value: NULL. There is a convention of writing it in capital letters as it is case sensitive.

  $nl = NULL;  
  echo $nl;   //it will not give any output