PHP vs JavaScript: When to Use


PHP vs JavaScript: When to Use

Developers used JavaScript and PHP to create several well-known websites, including Facebook (now also uses Hack, a PHP Dialect), Wikipedia, WordPress, and many others. Nevertheless, because PHP and JavaScript are both scripting languages, programming with them is difficult. PHP is a server-side scripting language, whereas JavaScript is a client-side scripting language. The two languages are adaptable and can work well together and separately. This article looks at PHP vs JavaScript. We outline the distinctions between the two languages and look at when to use them. 

Web Development

When it comes to web development, there are a plethora of programming languages, tools and important features you need to grasp before jumping into the web development process.

In web development, there are two categories: front-end and back-end development. Whatever you choose, you need to learn at least two to three programming languages. For the front end, you will need to learn HTML, CSS and JavaScript, while for the back end, you have lots of choices, such as Python, Java, PHP, and many more. 

However, if your goal is to become a full-stack developer, you need to master both front-end and back-end; you need to learn a handful of languages. This article will discuss PHP and JavaScript, two important and popular programming languages used to create dynamic web pages.

What is PHP?

Hypertext Preprocessor, also known as PHP, is a popular general-purpose, open-source programming language that is particularly well suited for server-side web development. Websites that are dynamic and interactive are made with PHP. The PHP code has a set of rules, is related to the HTML file or is embedded in the HTML code, and provides unique instructions for how to start and terminate processing.

PHP differs from JavaScript on the client in that the code is run on the server before being converted into HTML and given to the client. The results of running that script are delivered to the client, in this case, the browser, but the underlying code is concealed. A PHP script can transmit and receive cookies, create dynamic website content, and collect form input. Additionally, PHP scripts for desktop programs are possible.

PHP is a platform-independent programming language that runs on practically all major operating systems, including Microsoft Windows, macOS, RISC OS, Linux, and UNIX versions, and Web Servers like Apache and IIS. The PHP code syntax is fairly simple, but it follows a set of conventions and comes with a set of standard libraries to make web development much easier and more efficient. PHP allows developers to create dynamic web pages and connect them to powerful databases.

What is JavaScript?

JS, or JavaScript, is one of the world’s most popular and commonly used scripting languages. JavaScript is a programming language commonly used to create dynamic web pages, web and mobile applications, and games.

Since JavaScript is a client-side programming language, it runs on browsers, and thanks to its widespread popularity, most browsers can support JavaScript. Every browser has a JavaScript engine to execute code. SpiderMonkey and V8 are some engine browsers used to run js code.

Developers can create server-side JavaScript code by using cross-platform runtime engines like Node.js. The web market also offers a variety of JavaScript Frameworks, like AngularJS, ReactJS, NodeJS, etc. These frameworks drastically cut down on development time and effort for JavaScript-based websites and applications. In addition, JavaScript makes it simple for programmers to create complex web apps.

PHP vs JavaScript: Differences

Even though PHP and JavaScript are both scripting languages, many more characteristics set them apart. You should now understand from the above lines that JavaScript is a client-side language, whereas PHP is a server-side language. Now, we’ll look at additional differences you should be aware of in addition to these under the following headings:

  1. Language Type
  2. Open Source
  3. Concurrency
  4. Availability
  5. Concurrency
  6. Integration with External code
  7. Runtime Environments
  8. Simplicity
  10. Variables
  11. Objects & Arrays
  12. Platform Independent
  13. Security
  14. Database Access
  15. Learning Difficulty

Language Type

Scripting languages include JavaScript and PHP. PHP is a server-side language since the PHP code is run on the server, and the output is pure HTML code sent back to the browser as a response. JavaScript code is performed on the browser rather than the server because it is a client-side language.

Before Node.js was created, developers could only use JavaScript in a browser. An open-source, cross-platform runtime environment for JavaScript called Node.js allows JavaScript code to be executed outside of a browser. Before the page is transmitted to the user’s web browser, its developers create dynamic web page content using JavaScript for server-side scripting. Node.js eliminates the requirement for separate client-side and server-side languages.

PHP vs JavaScript: Open Source

PHP is an open-source programming language developed and maintained by a huge community with a strong support base. Because it is free, all you need to get started is a PHP parser, a web server such as Apache, and a web browser such as Google Chrome.

JavaScript is based on the ECMAScript standard, and many of its engines and frameworks, such as V8 and Node.js, are open-source. Developers can download JavaScript for free.

PHP vs JavaScript: Concurrency

PHP is traditionally synchronous and single-threaded, while JavaScript (with Node.js) is single-threaded but uses an event-driven, non-blocking I/O model to handle concurrency asynchronously. Developers use Ajax and JavaScript to make use of the asynchronous features. Ajax is a series of interconnected web development techniques used on the client-side to build asynchronous web applications. Ajax is asynchronous JavaScript and XML.

With Ajax, users may change specific information on a webpage without having to reload the page repeatedly. Social networking platforms, for instance, can update likes and dislikes without restarting the page after each activity.


Availability specifies the user who has the authority to edit it. PHP is a renowned open-source language, meaning its source code is freely available to the public. In addition, PHP is owned by the internet community and is open to revisions from its initial design. This is advantageous for PHP developers because there is a plethora of support provided by ordinary users.

JavaScript is an open standard program maintained by Ecma International and W3C.


Concurrency describes a process in which a task won’t be finished until every thread has finished processing. Thus, all threads start and end simultaneously. PHP’s multi-threaded blocking input/output feature allows for systematically executing many tasks simultaneously.

On the other hand, JavaScript is a functional single-threaded script that implements an event-driven model with non-blocking I/O execution, guaranteeing that everything runs sequentially.

PHP Vs JavaScript Integration with External code

PHP code can be integrated with HTML, XML, JSON, and other APIs (indirectly).

Contrarily, developers can use JavaScript code in conjunction with cutting-edge platforms like HTML, Ajax and XML.

Runtime Environments

There are many runtime environments for PHP and JavaScript. Each requires a different interpreter to run its code, although both are easily incorporated with HTML code. Zend Engine serves as both a compiler and a runtime engine for PHP, and it has a simple installation process. The dependability, extensibility, and performance of the Zend Engine all help explain why PHP is becoming increasingly popular.

Thanks to the development of Node js, a JavaScript runtime environment, JavaScript can now perform operations only possible with other server-side programming languages, such as restricted access to the information, data analysis, and tailored user experience. The V8 JavaScript runtime engine is used by Node.js and browser JavaScript alike.

PHP and JavaScript: Simplicity

JavaScript can be challenging to learn due to its event-driven architecture and asynchronous programming model, but it also offers extensive learning resources and community support.

Compared to JavaScript, PHP is easier to understand. PHP has a function for every operation you can think of. Because of its ease of use, PHP is used by many famous websites.

PHP Vs JavaScript: Comments

Programmers often add comments to their code to make the script simpler for people to understand. Compilers and interpreters usually overlook them. The coding below contrasts PHP and JavaScript comments by listing the sorts of comments that each language supports.


<?php //Single line PHP comment
# Single line PHP comment
/* Multi-line PHP comment */
echo "<p>This is PHP</p>";


//Single line JS comment
/* JavaScript
Multi-line JS comment */
alert('This is JS');

PHP Vs JavaScript: Variables

Unless expressed otherwise, PHP treats all variables as local. To declare a local variable in JavaScript, the developer should use let or const (introduced in ES6), or var (pre-ES6), as omitting these keywords will make the variable global.

PHP Variables:

In PHP, variables declared inside a function are local by default. To use a global variable inside a function, you need to explicitly declare it as global inside that function.

// Local variable example
function localVar() {
    $localVariable = 'value'; // Local variable 
    echo $localVariable;

// Global variable example
$globalVariable = 'value'; // Global variable

function globalVar() {
    global $globalVariable; // Declare global variable
    echo $globalVariable;

JavaScript Variables:

In JavaScript, variables declared with var, let, or const inside a function are local to that function. If you declare a variable without any keyword, it becomes global.

// Local variable example
function localVar() {
  let localVariable = 'value'; // Local variable using 'let'
  console.log(localVariable); // Print local variable

// Global variable example (not recommended) - Use with caution
var globalVariable = 'value'; // Global variable declared with 'var' (consider using 'let' or 'const' globally if necessary)

function globalVar() {
  globalVariable = 'new value'; // Access and modify global variable

// Avoid using implicitly global variables
function implicitGlobalVar() {
  // This line is commented out to avoid creating an implicit global variable
  // Consider using 'let' or 'const' instead if a variable needs to be accessible
  // outside of the function
  // implicitGlobal = 'value';
  console.log(implicitGlobal); // This line might throw an error if implicitGlobal is not defined elsewhere

// Call the functions to see the output
implicitGlobalVar(); // This might result in an error

Case Sensitivity is another area where PHP and JavaScript differ from each other. Despite the fact that both are case-sensitive when identifying variables, PHP is case-insensitive for function and class names, but variable names are case-sensitive. JavaScript is case-sensitive for all identifiers.

The boolean value “true” is accepted by PHP in both lowercase and uppercase. JavaScript, however, only recognises the keyword when it is all lowercase.

PHP Vs JavaScript: Objects & Arrays

PHP and JavaScript differ primarily in the way that objects and arrays are treated as distinct things with distinct syntaxes, but both are similar in JavaScript.

JavaScript enables unrestricted syntax switching between objects and arrays. Additionally, associative arrays are absent from JavaScript.

PHP Vs JavaScript: Platform Independent

PHP and JavaScript can run on any platform. All popular operating systems, including Linux, Windows, Mac, and Solaris, and popular web servers, including Apache, IIS, and Lighttpd, support PHP.

Any modern browser, including Safari, Firefox, and Chrome, can run JavaScript.

PHP Vs JavaScript: Security

Since PHP’s code is usually hidden from view in the browser, it is more secure than JavaScript. JavaScript code has a higher level of vulnerability.

Although security tools are not included with JavaScript, you can safeguard your JavaScript code by using Security Analyzer tools and adhering to standard development practices such as using SSL/HTTPS.

PHP Vs JavaScript: Database Access

PHP simplifies database access through server-side scripts. With Node.js, JavaScript can also perform server-side tasks, including database interactions, making it suitable for full-stack development.

Node.js allowed JavaScript to accomplish tasks that were previously only available to server-side languages.

PHP Vs JavaScript: Learning Difficulty

Since JS and PHP are interpreted languages, you can edit your code and then run it again to see the results without recompiling it.

JavaScript is a programming language rather than a markup language like HTML or CSS. Therefore, learning JavaScript will be simpler for you if you have programming knowledge.

Similarly, PHP is regarded as an accessible programming language. Both PHP and JavaScript have many internet resources and tutorials at their disposal.

When to Use PHP vs JavaScript

With the differences stated, you probably would have gotten an idea of the differences between PHP and JavaScript. If you are still wondering when to use them, consider the following.

Choose PHP as your backend language when your development project involves:

  • Solution stacks like Apache, MySQL, PHP, etc.
  • CMS like, WordPress, Joomla, etc
  • Servers like PostgreSQL, MariaDB, etc.

Pick JavaScript as your backend language when your development project involves:

  • Front-end development frameworks like Angular, React, etc.
  • Dynamic Single Page Applications
  • Technologies for servers, including MongoDB, Express.js, Node.js, etc.
  • Solutions Stacks like MEAN, Express js, MongoDB, etc.

PHP can have a slight advantage over JavaScript because of its open-source nature and ease of usage. To profit from the strengths of each, combine PHP and JavaScript rather than compare them.

The Bottom Line

Php and JavaScript languages come with a sample of features which is why developers use them in developing powerful websites and applications. However, developers need to understand the differences because they are both scripting languages, which confuses where and when to use them. We hope you learned about PHP and JavaScript and when to use them.

Experience JavaScript for free

If you want to experience JavaScript, try our free 5 Day Coding Challenge. In this short, free course, you will learn some basics of HTML, CSS and JavaScript. Register now through the form below. 

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