What is the difference between php5 and php7?

What is the difference between php5 and php7? The following article will compare php5 and php7 and introduce the differences between php5 and php7. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

The difference between php5 and php7:

1. Performance improvement: PHP7 has twice the performance improvement than PHP5.0 .

2. Many fatal errors in the past are now changed to throwing exceptions.

3. PHP 7.0 removes some old SAPI (server-side application programming port) and extensions that are no longer supported compared to PHP 5.0.

4. PHP 7.0 has a new null join operator than PHP 5.0.

5. PHP 7.0 has a new combined comparison operator than PHP 5.0.

6. PHP 7.0 adds a function return type declaration compared to PHP 5.0.

7. PHP 7.0 adds a new scalar type declaration compared to PHP 5.0.

8. PHP 7.0 has a new anonymous class compared to PHP 5.0.

9. Error handling and 64-bit support

If you understand the difference between errors and exceptions, then you will know that handling fatal errors in PHP 5 is not easy. PHP7 simplifies the process as it has replaced several major errors with exceptions that can be easily handled. This is achieved by introducing new engine exception objects.

You may already know that PHP 5 does not support 64-bit integers or large files, but that has changed in PHP 7. PHP7 has 64-bit support so you can use native 64-bit integers for large files as well, so you can run your application perfectly on 64-bit system architecture.

10. Declare the return type

In PHP 5, programmers cannot define the return type of a function or method. In real life, this is a huge disadvantage because the programmer has no way to prevent unexpected return types and generate exceptions in other situations.

Fortunately, PHP 7 allows programmers to declare the return type of a function based on the expected return value. This will definitely make the code robust and accurate. There are four different return types available - bool, int, string and float.

Why is the performance of PHP7 improved compared to PHP5?

1. Reduced variable storage bytes, reducing memory usage, and improving variable operation speed

2. Improved array structure, array elements and hash mapping table are allocated in the same memory Here, the memory usage is reduced, the CPU cache hit rate is improved

3, and the function calling mechanism is improved. By optimizing the parameter transfer link, some instructions are reduced and the execution efficiency is improved

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