Is there a big difference between php7 and php5?

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

10. Declaring return types

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 and the CPU cache hit rate is improved

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

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