PHP Data Types

Problem: State and briefly describe the PHP data type. (2010)

OR

How array is declared in PHP? Also explain various types of array with proper example.(2017)

Solve:

PHP supports the following data types:

Simple data types:

• String
• Integer
• Float / double
• Boolean
• Array 

Compound data types: 

• Object
• NULL 
• Resource

PHP Integers:

Integers are whole numbers, without a decimal point. Integer can be specified in decimal, hexadecimal, octal etc.

Example:

<?php

echo "PHP Data Type";

echo "<br>";  // for line break

//decimal number

$a = 50;

$b = 10;

$sum = $a+$b;

echo " Output=".$sum;

echo "<br>";  // for line break
echo "<br>";

// Negative number  

$a = -220;

$b = -20;
$sum = $a+$b;

echo " Output=".$sum;
echo "<br>";  // for line break

echo "<br>";

// Hexadecimal number
$a = 0x2b;

echo $a;
echo "<br>";  // for line break

echo "<br>";

// Octal number

$a = 0321;

echo $a;

?>

Screenshots of Source code:

Output:

PHP Data Type
Output=60

Output=-240

43

209

Screenshots of Output:

PHP Floating Numbers or Doubles:

Floating point numbers are decimal or fractional numbers.

Example:

<?php

echo "PHP Floating or Doubles number";

echo "<br>";  // for line break

echo "<br>"; 

$a = 22.8;  //Floating numbers
echo "Float Number  a = ".$a;
echo "<br>";  // for line break

$b =  8.3;
echo "Float Number b  = ".$b ;

$sum = $a+$b;
echo " Output Float =".$sum;
?>

Screenshots of Source code:

Output:

PHP Floating or Doubles number

Float Number  a = 22.8
Float Number b  = 8.3
Output Float = 31.1

Screenshots of Output:

PHP Strings:

Strings are sequence of characters.

<?php
echo "PHP String";
echo "<br>";  // for line break
echo "<br>"; 

$name = "Tarikul Islam Tufan!";  // String data type
echo "The name of  the programmer is".",". $name;
echo "<br>";

// or
$a = 'CSE';
echo "String=".$a;
?>

Screenshots of Source code:

Output:

PHP String

The name of  the programmer is
String=CSE

Screenshots of Output:

PHP Boolean:

Booleans are like a switch it has only possible either 1 (true) or 0 (false).

Example:

<?php
echo "PHP Boolean";
echo "<br>";  // for line break
echo "<br>"; 

//Assign the value TRUE to a variable
$show_error = TRUE;
echo $show_error;
echo "<br>";  // for line break

// or
if(TRUE)
echo "This condition is True";
if(FALSE)
echo "This condition is not True";
?>

Screenshots of Source code:

Output:

PHP Boolean

1
This condition is True

Screenshots of Output:

Also explain various types of array with proper example.(2017)

PHP Arrays:

An array stores multiple values in one single variable.
There are three types of arrays that you can create. These are:

1. Indexed array
2. Associative array
3. Multidimensional array

Indexed array: An array with a numeric key. In an indexed or numeric array, the indexes are automatically assigned and start with 0, and the values can be any data type.

Example:

<?php
echo "PHP Array";
echo "<br>";  // for line break
echo "<br>"; 

$name  = array("Tufan","Tarukul","Basu");
print_r($name);  //Printing array structure
echo "<br>";  // for line break
echo "<br>"; 
//or
echo "$name[0]";
echo "$name[1]";
echo "$name[2]";
?>

Screenshots of Source code:

Output:

PHP Array

Array ( [0] => Tufan => Tarukul [2] => Basu)
TufanTarukulBasu

Screenshots of Output:

Associative Array: An array where each key has its own specific value.In an associative array, the keys assigned to values can be arbitrary and user defined strings. In an associative array uses keys instead of index numbers:                                                                                                                 
Example:

<?php
echo "PHP Associative Array";
echo "<br>";  // for line break
echo "<br>"; 
$name  = array("Tufan"=>22,"Tarukul"=>25,"Basu"=>30);
print_r($name);  //Printing array structure
echo "<br>";  // for line break
echo "<br>"; 
//or
echo $name['Tufan'];
echo "<br>"; 
echo $name['Tarukul'];
echo "<br>"; 
echo $name['Basu'];
?>

Screenshots of Source code:

Output:

PHP Associative Array

Array ( [Tufan] => 22 [Tarukul] => 25 [Basu] => 30)

22
25
30

Screenshots of Output:

Multidimensional array: An array containing one or more arrays within itself.

Example:
<?php
echo "PHP Multidimensional Array";
echo "<br>";  // for line break
echo "<br>"; 
//Define array
$contacts = array(
array(
"name" => "Tarikul islam tufan",
"email"=> "tufan@gmail.com",
"phone"=> "01765779616",
),
array(
"name" => "Tarikul islam tufan",
"email"=> "tufan@gmail.com",
"phone"=> "01956353863",
),
array(
"name" => "Tarikul islam tufan",
"email"=> "tarikul@gmail.com",
"phone"=> "01956353863",
),
);
// Access values
echo "Tarikul islam tufan`s name is:".$contacts[0]["name"];
echo "<br>"; 
echo "Tarikul islam tufan`s email is:".$contacts[1]["email"];
echo "<br>"; 
echo "Tarikul islam tufan`s phone is:".$contacts[2]["phone"];
?>

Screenshots of Source code:

Output:

PHP Multidimensional Array

Tarikul islam tufan`s name is:Tarikul islam tufan
Tarikul islam tufan`s email is:tufan@gmail.com
Tarikul islam tufan`s phone is:01956353863

Screenshots of Output:

PHP Object: 

An object is a data type which stores data information on how to process that data.
In an object array, first we must declare a class of object.For this, we use the class keyword.

Example:

<?php
echo "PHP Object Data";
echo "<br>";  // for line break
echo "<br>"; 
class car {
function car(){
$this -> model = "BMW";

}

}

//create an object

$message = new car();

echo $message -> model;?>

Screenshots of Source code:

Output:

PHP Object Data

BMW

Screenshots of Output:

PHP NULL Value: 

Null is a special data type which can have only one value:- NULL. It is used to represent empty variables in PHP.

Example:

<?php
echo "PHP NULL Data";
echo "<br>";  // for line break
echo "<br>"; 
echo "No output";
$a = "tufan";
$a = NULL ;
echo $a; 
?>

Screenshots of Source code:

Output:

PHP NULL Data

No output

Screenshots of Output:

PHP Resource: 

The special resource type is not an actual data type. These are basically used to store reference to some function call or to external PHP resources.

Example:

<?php
// Open a file for reading 
$Book = fopen("note.txt","r");
var_dump($Book);
//  Connect to MySQL Database server Required 
?>

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