Require()
The Require() is used to include a file, It create fatal error if file not found and terminate script.
The require_once() to require() except PHP will check if the file has already been included, and if so, tricor online not include (require) it again.
include ()
The include () is used to include a file, It create warning if file not found and execute script.
include_once()
The include _once() statement include () except PHP will check if the file has already been included, and if so, not include (include) it again.
There are 4 methods to includes files
require()
require_once()
include()
include_once()
There are number of superglobal variables in php
cURL is a library which allows you to connect and communicate to many different types of servers with many different types of protocols. Using cURL you can:
PHP cURL library is definitely the odd man out. Unlike other PHP libraries where a whole plethora of functions is made available, PHP cURL wraps up a major parts of its functionality in just four functions.
A typical PHP cURL usage follows the following sequence of steps.
curl_init – Initializes the session and returns a cURL handle which can be passed to other cURL functions.
curl_opt – This is the main work horse of cURL library. This function is called multiple times and specifies what we want the cURL library to do.
curl_exec – Executes a cURL session.
curl_close – Closes the current cURL session.
Below are some examples which should make the working of cURL more clearer.
The below piece of PHP code uses cURL to download Google’s RSS feed.
<?php
/**
* Initialize the cURL session
*/
$ch = curl_init();
/**
* Set the URL of the page or file to download.
*/
curl_setopt($ch, CURLOPT_URL,
‘http://news.google.com/news?hl=en&topic=t&output=rss’);
/**
* Ask cURL to return the contents in a variable
* instead of simply echoing them to the browser.
*/
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
/**
* Execute the cURL session
*/
$contents = curl_exec ($ch);
/**
* Close cURL session
*/
curl_close ($ch);
?>
As you can see, curl_setopt is the pivot around which the main cURL functionality revolves. cURL functioning is controlled by way of passing predefined options and values to this function.
The above code uses two such options.
Juggling means
throwing and catching several objects simultaneously.
Type Juggling in php means automatically type conversion.
That is to say, if a string value is assigned to variable $var, $var becomes a string. If an integer value is assigned to $var, it becomes an integer.
Please see Example.
<?php
$var = "0";// $var is string (ASCII 48)
$var += 10; // $var is now an integer (10)
$var = $foo+ 1.5; // $var is now a float (11.5)
$var = 5 + "10 Little hots"; // $var is integer (15)
$ var = 5 + "10 Small hots"; // $var is integer (15)
?>
$var variable comes many times in different data type.
Often it became interger, float.
This is Type Juggling in php.
Thank you
PHP supports 8 data types.
Explaination:
4 scalar types:
boolean
<?php
$var = True; // assign the value TRUE to $foo
?>
integer
<?php
$var = 123; // decimal number
$var = -122; // a negative number
$var = 0111; // octal number
$var = 0x1B; // hexadecimal number
?>
float (floating-point number, aka double)
<?php
$var = 1.234;
$var= 1.2e3;
$var = 7E-10;
?>
string
<?php
$string =”Hello World”; // Assign Hello World into $string
?>
2 compound types:
array
<?php
$array = array(“first”=>”Hello”,”second”=>”World”);
echo $array[‘first’];
echo $array[‘second];
?>
object
<?php
Class Interview
{
Function php()
{
Echo “What is php”;
}
}
$obj = new Interview(); // $obj is object , you can also take different name like $object,$interview
Echo $obj-> php();
?>
3 compound types:
resource
NULL
<?php
$variable = NULL;
?>
Note: PHP does not require to define variable in in any specific data type. Like integer,float,string etc, like C,C++.
PHP support automatic type conversion .
For More Detail see Type Juggling articles.
Thank you
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