What is the difference between PHP 5 and PHP 7?

The Hypertext Preprocessor (PHP) is a very popular scripting language. It’s been a standard since 1994 due to its attractive features. Safer connectivity to the database, faster speed, runs smoothly on the most used platforms (Windows, Unix, Linux). Of course, there were many improvements, but let’s have a closer look at PHP 5 and PHP 7.

PHP 5 main features.

PHP5 was developed considerably more robust than PHP 4. The Zend II engine powered it. It offered an improved mechanism for handling exceptions and errors, a model oriented to objects that supplies interfaces, abstract classes, constructors, static and final properties. Besides, it had SSL connections, multi-query functions for MySQL extension. PHP5’s XML extensions were enhanced, just like the soap implementation for providing and consuming web services, speed, and performance.

PHP 7 main features.

PHP 7 was the successor of PHP 5. Its performance was better than the PHP 5. It was powered by a PHP-NG (Next Generation) engine. It achieved twice the PHP 5 performance and 50% less memory consumption to give a reference. It added anonymous classes, removal of deprecated methods, better exception hierarchy and handling, more efficient memory use, abstract syntax tree, and support for return type declarations. Besides, it included scalar type declarations for better controlling the code, CSPRNG functions, spaceship operator (three-way comparison), constant arrays using define (). 

What is the difference between PHP 5 and PHP 7?

  • Performance. And PHP 7 speed got double than the one offered by PHP 5. While PHP 5 (Zend II engine) handled an average of 22 requests per second, PHP 7 (PHP-NG engine) made 44. So PHP 7 totally boosted the scripting performance and websites’ loading speed.
  • Exception handling. Handling fatal errors with PHP 5 was hard for developers, mostly because errors were not displayed directly. You needed to trace the information to find it and to identify if it was fatal or not for an application. On PHP 7, important errors became exceptions to be caught easier.
  • Return type. PHP5 didn’t include a provision for return type declarations. This feature was added to PHP 7 version, making the code more accurate. The available return types were: float, string, bool, int.
  • Null coalescing operator ?? On PHP 5, you had to write explicit code to return the null value in the case the value was not available (it didn’t exist). On PHP 7, you could just use the operator ?? (two question marks) to return a variable’s value if it was available or for returning null if it was not available.
  • Spaceship operator (combined or three-way comparison). With PHP 5, many different operators were used for comparing. PHP 7 integrated the three-way comparison operator (<=>), meaning that with a single operator, three kinds of comparisons were possible to do simultaneously: greater than, less than, and equal. It returned 0, meaning equal, -1 if the right part was greater than the left, and 1 in the opposite scenario.
  • Declarations. PHP 5 worked with individual declarations for namespaces. PHP 7 simplified the task through the use of group declaration. This made code more compact and easy to read. It definitely meant less time typing for programmers. 
  • 64-bit support. While PHP5 didn’t support 64-bit, PHP7 did, the complete 64-bit and large files. Running applications smoothly on these architectures was not a problem anymore.
  • Anonymous class. It was included on PHP 7. Then, creating a complete definition of a class required just once in the whole application was not needed anymore. Instead, an anonymous class for a single-use got possible. 


The jump from PHP 5 to PHP 7 was key for PHP to evolve and become a more useful scripting language. Currently, we are on PHP 8 (8.0.8 version). Stop imagining the possibilities. Better experience them now!

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