PHP Booleans Data type

A Boolean represents two possible states: TRUE or FALSE. It can be either TRUE or FALSE.  It is often used in conditional testing.

Example :

<?php
$var1 = True; // assign the value TRUE to $foo
var_dump($var1); // function returns the data type and value.
?>

Output :

boolean true

---

PHP Integers Data type

An integer is a number of the set ℤ = {..., -2, -1, 0, 1, 2, ...}.

Rules for integers:

• An integer must have at least one digit

• 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)

Example :

<?php
 $var1 = 1234; 		// decimal number
 var_dump($var1);	// function returns the data type and value.
 $var2 = -123; 		// a negative number
 var_dump($var2); 	// function returns the data type and value.
 $var3 = 0123; 			// octal number (equivalent to 83 decimal)
 var_dump($var3); 	// function returns the data type and value.
 $var4 = 0x1A; 			// hexadecimal number (equivalent to 26 decimal)
 var_dump($var4); 	// function returns the data type and value.
?>

Output :

int 1234
int -123
int 83
int 26

---

PHP Float Data type

Floating point numbers (also known as "floats", "doubles", or "real numbers") are decimal or fractional numbers, like demonstrated in the example below.

Example :

<?php
 $var1 = 5.234;
 var_dump($var1); // function returns the data type and value.

 $var2 = 5.3e5;
 var_dump($var2); // function returns the data type and value.

 $var3 = 4E-8;
 var_dump($var3); // function returns the data type and value.
?>

Output :

float 5.234
float 530000
float 4.0E-8

---

PHP String

A string is a sequence of characters, where a character is the same as a byte. This means that PHP only supports a 256-character set.

A string always written in single quotes or double quotes .

Example :

<?php 
$var1 = "Jawab Adda";
$var2 = 'Jawab Adda';
var_dump($var1); // function returns the data type and value.
var_dump($var2); // function returns the data type and value.
?>

Output :

string 'Jawab Adda' (length=10)
string 'Jawab Adda' (length=10)

---

PHP Array

Array is collection of values a single array stores multiple values. An array can be created using the array() language construct

In PHP, there are three types of arrays:

• Indexed arrays - Arrays with a numeric index

• Associative arrays - Arrays with named keys

• Multidimensional arrays - Arrays containing one or more arrays

Example :

<?php 
$lang = array("HTML","PHP","MYSQL");
var_dump($lang);// function returns the data type and value.
?>

Output :

array
  0 => string 'HTML' (length=4)
  1 => string 'PHP' (length=3)
  2 => string 'MYSQL' (length=5)

---

PHP Object

objects, which can contain variables and  methods (functions)  In PHP, an object must be explicitly declared.

class keyword used to declare class in php A class is a structure that can contain properties and methods.

Example :

<?php 
class Book {
    function Book() {
        $this->name = "PHP Language";
    }
}

$obj = new Book();// create an object
echo $obj->name;// show object properties
var_dump($obj);// function returns the data type and value.
?>

Output :

PHP Language
object(Book)[1]
  public 'name' => string 'PHP Language' (length=12)

---

PHP Null

Null is a only data type which can have only possible value is NULL this mean it can have only one value : Null

Suppose if we declare a variable without a assign any value then  it is automatically assigned a value of NULL  

A variable is considered to be null if:

• it has been assigned the constant NULL.
• it has not been set to any value yet.
• it has been unset().

Example :

<?php
$var = "Jawab Adda";
$var = null;
var_dump($var);// function returns the data type and value.
?>

Output :

null

---

PHP Resources

A resource is a special variable, holding a reference to an external resource.

Resource variables typically hold special handlers to opened files and database connections.

Example :

<?php
// Open a file for reading
$handle = fopen("filename.txt", "r");
var_dump($handle);// function returns the data type and value.
?>

Output :

resource(3, stream)