A practical guide to the underlying development principles of PHP7: Master the debugging and optimization skills of the PHP kernel

A practical guide to the underlying development principles of PHP7: Master the debugging and optimization skills of the PHP kernel

Introduction:
PHP is currently the most widely used dynamic web page programming in the world One of the languages. Its simplicity, ease of learning, powerful functions, and large developer community make PHP widely used in the field of Web development. However, understanding the underlying development principles of PHP is a valuable skill for developers. This article will introduce the principles of underlying development of PHP7 and provide debugging and optimization techniques to help developers write and optimize PHP code more efficiently.

1. Introduction to the underlying development principles of PHP7

1. Main features of PHP 7
   PHP 7 is an important version of the PHP language, bringing many new features and Improve. Some of the important features include:

   • Performance improvements: PHP 7 introduces the new Zend engine, which greatly improves the performance of PHP, making it faster than previous versions.
   • Scalar type declaration: PHP 7 allows developers to declare scalar types in function parameters and return values, thereby enhancing the type safety of the code.
   • Anonymous class and return type declaration: PHP 7 supports anonymous class and return type declaration, making the code more concise and readable.
   • Error handling improvements: PHP 7 introduces the Throwable interface and Error exception class, which improves the error handling mechanism.
   • New operators: PHP 7 introduces the Spaceship operator and the Null coalescing operator, making the code more concise and flexible.

2. PHP 7 underlying architecture
   The underlying architecture of PHP 7 mainly includes the following parts:

   • Zend engine: Zend engine is PHP 7's core component, responsible for parsing and executing PHP code. It includes lexical analyzer, syntax analyzer, compiler and executor, etc.
   • Zend Core: Zend Core provides basic functions and class libraries required for PHP development, such as string processing, file operations, database access, etc.
   • Extension modules: PHP 7 supports extension modules to increase its functionality. The extension module is written in C language and interacts with PHP through PHP's extension API.
   • C language library: PHP 7 relies on some C language libraries at the bottom level, such as libxml, libjpeg and libmysql.

2. PHP7 debugging skills

1. Use the var_dump() function
   The var_dump() function can print out the value and type of the variable. Help developers understand the data structure in the code. This is very helpful for debugging complex code. The following is an example:

$name = "John";
$age = 25;
var_dump($name, $age);

The output is as follows:

string(4) "John"
int(25)

2. Use Xdebug extension
   Xdebug is a debugging and performance analysis tool for PHP that can provide powerful Debugging features such as breakpoint debugging, stack tracing, and variable viewing. To use the Xdebug extension, you first need to download and install it. The Xdebug extension can then be enabled in the PHP configuration file. Next, set a breakpoint in the IDE, and then access the corresponding page in the browser. Xdebug will stop at the breakpoint and you can perform debugging operations.

3. PHP7 optimization tips

1. Use code caching
   Code caching can greatly improve the execution speed of PHP scripts. The code caching tool will cache the bytecode of the PHP script into memory to avoid re-parsing and compiling the script for each request. Some commonly used code caching tools include APC, OPcache, Xcache, etc.
2. Reduce function calls
   Function calls are a time-consuming operation in PHP scripts. In order to improve performance, you can try to avoid using too many functions and try to encapsulate some common operations into functions to avoid repeated calls.
3. Use appropriate data structures
   In PHP, different data structures have different performance characteristics. Using the right data structures can significantly improve the performance of your code. For example, if you need to find and insert data frequently, using a hash table (HashTable) may be a good choice.
4. Avoid using global variables
   The use of global variables may reduce the readability and maintainability of the code, and may also cause some performance problems. Therefore, you should try to avoid using global variables and instead pass data through function parameters or class member variables.

Conclusion:
This article introduces the principles of underlying development of PHP7 and provides debugging and optimization techniques. Understanding the underlying development principles of PHP is a valuable skill for developers and can help them write and optimize PHP code more efficiently.

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