What is the difference between include and require in program PHP?

Before answering this question i’ll brief you about why we use include() and require() in PHP -

To insert the content of one PHP file into another PHP file before the server executes it.

Now, little more details about include() and require() -

include() - it includes a specified file. it will produce a warning if it fails to find the file and execute the remaining scripts. include() should be used when the file is not required and application flow should continue when the file is not found.

Syntax -

include ‘filename’;

——————————————————-

instead of using include() we can use include_once(),

include_o

Before answering this question i’ll brief you about why we use include() and require() in PHP -

To insert the content of one PHP file into another PHP file before the server executes it.

Now, little more details about include() and require() -

include() - it includes a specified file. it will produce a warning if it fails to find the file and execute the remaining scripts. include() should be used when the file is not required and application flow should continue when the file is not found.

Syntax -

include ‘filename’;

——————————————————-

instead of using include() we can use include_once(),

include_once() - it also includes a specified file but if a file has already been included. it will not be included again. it’ll also produce a warning if it fails to find the file and execute the remaining scripts.

syntax -

include_once();

require() - it also includes a specified file but it will throw a fatal error (E_COMPILE_ERROR) if it fails to find the file and stops the execution.

syntax -

require ‘filename’;

——————————————————-

instead of using require() we can use require_once(),

require_once() - it also includes a specified file but if a file has already been included. it will not be included again. it will throw a fatal error (E_COMPILE_ERROR) if it fails to find the file and stops the execution.

syntax -

require_once();

Now, let us see the difference between include() and require() -

Let’s understand the difference through an example-

Assume we have a file called “babu.php” with some variables defined;

  1. <?php
  2. $baby="beautiful";
  3. $love="girl";
  4. ?>

but, here we are not gonna include “babu.php” because here we’ll differentiate include() and require() -

  1. <html>
  2. <body>
  3. <h1> Coder Anand Welcomes You..!<h1>
  4. <?php
  5. include 'noFileExixts.php';
  6. echo "Choti is a $baby$love";
  7. ?>
  8. </body>
  9. </html>

Results of above scripts using include() will be-

Coder Anand Welcomes You..!

Choti is a

If we do the same example using require statement,the echo statement will not be executed because the script execution dies after the require statement returned a fatal error (E_COMPILE_ERROR) -

  1. <html>
  2. <body>
  3. <h1> Coder Anand Welcomes You..!<h1>
  4. <?php
  5. require 'noFileExixts.php';
  6. echo "Choti is a $baby$love";
  7. ?>
  8. </body>
  9. </html>

Results of above scripts using require() will be-

Coder Anand Welcomes You..!

Difference :-

  • require will produce a fatal error (E_COMPILE_ERROR) and stop the script execution.
  • include will only produce a warning (E_WARNING) and the script will continue.

Note :-

  • Use require() when the file is required by the application.
  • Use include() when the file is not required and application should continue when file is not found.

Thank You for reading :)

Happy Learning & Coding :)

Anand Baraik :)

The include (or require) statement takes all the text/code/markup that exists in the specified file and copies it into the file that uses the include statement.

Including files is very useful when you want to include the same PHP, HTML, or text on multiple pages of a website.

The only difference is — the include() statement will only generate a PHPwarning but allow script execution to continue if the file to be included can't be found, whereas the require() statement will generate a fatal error and stops the script execution.

They differ in the errors they throw when the file they request is not found.

Include will only throw a warning, and afterwards the program will continue to execute.

Require however will throw a fatal error, after-which the program will halt and stop any further execution.

Other than that they behave exactly the same.

well, we can include another PHP file into current PHP file, with help of include & require statement.

Difference between include & require statement:

  • require will produce fatal error ( E_COMPILE _ERROR ) and stop the script.
  • include will produce only warning ( E_WARNING ) and script will continue.

Hope it will help you…

include doesn’t show any error and run the remaining code continue while require throw fatal error if file not found and stop the execution of the code.

To know more about on going project on php, you may like to visit here; http://www.indoscie.com

Require and include functions does the same task i.e. includes and evaluates specified file, but the difference is require will cause a fatal error when the specified file location is invalid or for any error where as include will generate a warning and continue the code execution.

If a required file is not found PHP will emit a fatal error whereas for include only a warning will be emitted. include() will throw a warning if it can't include the file, but the rest of the script will run.

Require and include do the same task but the main difference is require will cause a fatal error when the specified file location is invalid or for any error where as include will generate a warning and continue the code execution.

Hope this helps!

The require() generates a fatal error, and the script will stop whereas the include() function generates a warning, but the script will continue execution.

_Aravind

I would say PHP is probably, while not a solution for every problem, a solution to many more problems than your average popular language (node, python, ruby, java, and so on).

I work at a company as the Lead / Senior Developer. We run about 600 heavy traffic websites using primarily PHP. All of this is managed by an incredibly small team of three backend developers (including myself), and two designers.

Before I write a glowing review of PHP, I want to point out, I regularly write code in a very wide variety of languages: Node.js/Javascript, Lua, Python, C#, C/C++, Bash, and Ruby, just to name a

I would say PHP is probably, while not a solution for every problem, a solution to many more problems than your average popular language (node, python, ruby, java, and so on).

I work at a company as the Lead / Senior Developer. We run about 600 heavy traffic websites using primarily PHP. All of this is managed by an incredibly small team of three backend developers (including myself), and two designers.

Before I write a glowing review of PHP, I want to point out, I regularly write code in a very wide variety of languages: Node.js/Javascript, Lua, Python, C#, C/C++, Bash, and Ruby, just to name a few.

Every problem needs the correct solution. If you are to say “This project will be written in {Any Language} and nothing else”, then that is just silly. Some problems will just be better solved in particular languages.

What I will say, is PHP, by far, has in my opinion the perfect balance between:

  • Applicability: PHP can solve a very wide variety of issues. It’s not limited to just web requests.
  • Time to get a project off the ground: I don’t think any langage can rival PHP here.
  • Long Term Maintainability: Just about any code properly written for PHP 5.x should also still work today, it was released in the year 2004!
  • Evolution of syntax: Some languages just let themselves go stale and don’t adapt to the rapidly changing pace of development. More on this in a moment.

So why would you want to use PHP? Here are some practical observations from my 5 years of working as the senior developer at my current company:

  • The language is evolving and improving at an incredibly fast rate while keeping things very backwards compatible. We have code that was written in 2012 that still runs flawlessly. Our new code, we can utilize new language features (in PHP 7.x) like type-hinting, and new libraries. This code works fine side-by-side. The language has undoubtedly stood the test of time. PHP is, for the most part, making improvements precisely where it should be.
  • It’s served us well for our back-end development. Modern PHP has an extremely rich object oriented syntax. Any developer worth his or her weight in salt should be very capable of designing a large, enterprise system with PHP.
  • PHP is no longer “slow” and in fact is much faster than most interpreted language, especially since PHP 7.x. It also is no longer “leaky” or “unstable” (which, it really used to be!).
  • Until we finally made the switch to Twig, it served us very well for the first 4 years for front-end (template) development. PHP itself can still work as a fairly decent template language by itself (commonly called phtml).
  • It’s also served us far beyond just front-end and back-end web development. Right now, we use pure PHP scripts for long-running, large service workers (daemons) and console scripts. Many people may argue here, but there is absolutely nothing wrong with this. PHP is NOT the same “leaky” language it was in 2005! It’s perfectly capable of running network and service daemons with a little forethought.
  • Works well with an extremely wide array of databases, third party infrastructure: We use mySQL, Redis, ElasticSearch, Amazon DynamoDB, ourselves internally. We also routinely access remote Microsoft SQL, and PostgreSQL databases. All of these things are extremely well-supported by PHP. You’ll be hard-pressed to find a database or third party service that doesn’t directly support PHP.
  • If you do, it should be very easy to make a library to support it. If for some crazy reason the PHP language falls short, then C-language extensions in PHP are becoming easier and easier every release, and while a bit advanced, certainly can remove any remaining barrier your application may be up against.
  • Very easy to use, and learn. Our front-end developers have no problem with basic PHP.
  • A large amount of high-quality libraries and frameworks already prewritten. It takes no time to get a fairly complex CRUD project from specs to delivery.
  • A fairly decent (although, not the best) package manager for those libraries (composer)
  • Enormous community base.
  • Excellent documentation.

However, nothing is without it’s cons:

  • A lot of tutorials and code snippets are extremely out of date and exhibit what would now be considered really bad practice.
  • Composer could be better.
  • The language still suffers from some unusual issues not seen in other languages. For example, some “errors” still throw “PHP Warnings”, “PHP Erorrs”, instead of throwing an exception like they should. This is rapidly changing, and shouldn’t be a problem much longer. The way typecasting can still be confusing for novices. Once again, however, this is slowly going away with the recently implemented “strict mode”.
  • We have fairly serious problems integrating things like SCSS compilers, PostCSS, and other tools designed for front-end development, which are typically node.js based.
  • Serving an large amount of concurrent requests can be a real challenge with PHP. While it certainly isn’t impossible, it requires additional skill and honest infrastructure planning that you would normally not require for other web languages.
  • As with anything, you will need serious planning to get a large project off the ground. While it would be ridiculous to call this a PHP-only problem, I believe that PHP projects can suffer far more dire consequences of poor planning than comparable languages.

So, to sum things up:

PHP works. PHP has always worked. It will continue to work. It has, in my opinion, evolved and improved itself more than any other programming language I can come up with. And in a positive direction. The PHP team is seemingly very honestly focused on fixing the issues of today.

There is a reason more of the world’s top websites use PHP as their language than any other.

We still use C#, Lua, Java, and Node.js and server-side code here and there, but for the vast majority of things, PHP just makes sense for us, and will continue to make sense for us.

PHP 7 was released in December 2015.

The features of PHP7 are fairly enough for advance web application development and making use of latest resources to boost you development. There are lot of talks about PHP5.7, PHP6 or PHP 7. The main reason behind the PHP7 is PHP6 has never reached to stable version, also there are many resources available about PHP6. So PHP community has chosen PHP5.6 to directly PHP7.

Let us get into some details:-

1. Performance:

You might have heard about Facebook HVVM out there, to provide you maximum performance for PHP based application. So PHPNG (PHP-Next-Gen) started

PHP 7 was released in December 2015.

The features of PHP7 are fairly enough for advance web application development and making use of latest resources to boost you development. There are lot of talks about PHP5.7, PHP6 or PHP 7. The main reason behind the PHP7 is PHP6 has never reached to stable version, also there are many resources available about PHP6. So PHP community has chosen PHP5.6 to directly PHP7.

Let us get into some details:-

1. Performance:

You might have heard about Facebook HVVM out there, to provide you maximum performance for PHP based application. So PHPNG (PHP-Next-Gen) started with the idea to provide maximum performance as Facebook HVVM provides. The performance improvement source was led by ZEND to speed up PHP based applications. As per Zend performance improvement is huge! You can find some benchmark against HVVM here. Without changing single piece of code, just upgrading to PHP7 gives you enormous performance. Deprecating many redundant features also part of performance improvement of PHP7.

2.Scalar Type Hints & Return Types:

While many developers would like able to declare return type for the function or method. By default PHP7 will allow developers to declare what kind of return type function is expected to return a value. It is almost similar as Type hinting parameters as below.

Example:

  1. public function isValidUser(int $id) : bool
  2. {
  3. return isset($this->users[$id]) ? true : false;
  4. }

Above example is similar as Facebook HACK syntax. In this example bool indicates the function will return only boolean value. You can also have look at many example in RFC here. This allows developers to set expecting strings, int, float or bool to be passed or returned.

3.Spaceship Operator

PHP7 will introduce a new operator called spaceship operator (<= >) otherwise called combined comparison operator. It can be used mostly in sorting and combined comparison. It works like strcmp() or version_compare().

As per the PHP RFC common uses of sorting as below.

Example:

  1. Before PHP7:
  2. function order_func($a, $b)
  3. {
  4. return ($a < $b) ? -1 : (($a > $b) ? 1 : 0);
  5. }

then,

  1. After PHP7:
  2. function order_func($a, $b)
  3. {
  4. return $a <=> $b;
  5. }

It is a beautiful addition to the PHP version. You can find more example here.

4.Additional Features

Apart from above changes there are few new features added into the PHP7 core. I am listing few major changes below.

  • Abstract Syntax Tree: – Another big change on the core. But most likely to be visible to developers. It makes parsing php code easier, less error, and way to build better things in future.
  • Closure::call() : – This is the new method added into core. It allows variable binding at call time rather pre-binding.
  • Null Coalesce Operator : – The coalesce operator or ?? added to the core, which returns the first operand if exists or null.

Example:

  1. //Before PHP7:
  2. $id = isset($_GET[‘id’]) ? $_GET[‘id’] : null;
  3. In PHP7:
  4. $id = $_GET[‘id’] ?? null; //equivalent of writing old above syntax
  • Uniform Variable Syntax : – The main deference of existing syntax and new syntax is to keep consistence and complete variable syntax. Allows advance expressions.

Example:

  1. $$foo['bar']['baz'] interpreted as ($$foo)['bar']['baz']
  2. $foo->$bar['baz']() interpreted as ($foo->$bar)['baz']()
  • Unicode Codepoint Escape Syntax: – PHP7 introduced syntax to escape unicode codepoint as below.

Example:

  1. echo "\u{202E}Reversed text"; // outputs Reversed text
  2. echo "\u{1F602}"; // outputs ��

5.Cleanups:

Developers can stop recognizing method name as class name to be a constructor as per PHP4 . It has been controversial early to remove but later has been removed completely as currently we no longer required to warn PHP developer how PHP4 works. This removal added as simplicity.

mysql_* functions are completely removed as extension removed by default.

Multiple default clause support has been removed from the switch case.

Support of ASP tags (<%) and script tags ( ) has been removed meaning that you can't use those tags to enter php mode.

You can find more, list of deprecated or removed functionalities here, Removed deprecated functionalities in PHP7

Conclusion:

Personally I believe recent changes of PHP versions, makes PHP as much more matured language. But it is good message to all PHP developers for building awesome enterprise level applications using latest PHP version.

Source : stackoverflow