Exploring the underlying development principles of PHP7: cracking the operating mechanism of the PHP virtual machine

Exploring the underlying development principles of PHP7: cracking the operating mechanism of the PHP virtual machine

Overview:
PHP is a scripting language widely used in website development, and PHP7 is the latest version in the PHP series. After many iterations and optimizations, PHP7 has made a qualitative leap in performance. To understand the underlying development principles of PHP7, we need to have an in-depth understanding of the operating mechanism of the PHP virtual machine in order to better understand and optimize our PHP code. This article will reveal the operating mechanism of the PHP virtual machine by exploring the underlying development principles of PHP7.

1. Overview of PHP virtual machine
The PHP virtual machine is the core component of the PHP interpreter, which is responsible for parsing and executing PHP code. In PHP7, the PHP virtual machine uses Zend Engine 3.0 as its core engine, and its architecture is more flexible and efficient.

2. PHP7 underlying development principle

1. Internal data structure of Zend engine
   PHP7 adopts a new type of internal data structure called Zend memory manager. The Zend memory manager uses an order called "BIG_ENDIAN" to store data, which makes the allocation and management of data in memory more efficient.
2. Parsing process of PHP script
   The parsing process of PHP code includes two steps: lexical analysis and syntax analysis. In the lexical analysis stage, the PHP code is parsed into individual tags, including keywords, variable names, etc. During the syntax analysis phase, PHP code is parsed into an abstract syntax tree (AST).
3. Execution process of PHP virtual machine
   When the PHP virtual machine executes the PHP code, it will interpret and execute each node in the abstract syntax tree (AST) in a certain order. Specifically, the PHP virtual machine first compiles each node in the AST into bytecode, then converts the bytecode into machine code and executes it.

3. Sample code
In order to better understand the underlying development principles of PHP7, let’s look at the following sample code:

<?php
function add($a, $b) {
    return $a + $b;
}

$result = add(2, 3);
echo $result;
?>

In this example, we define a A function named add that accepts two parameters and returns their sum. Then we call the add function, assign the return result to the $result variable, and finally print out $result.

In the underlying implementation of PHP7, the above code will be compiled into bytecode and then executed in the virtual machine. The virtual machine performs operations such as function calling, parameter passing, and variable assignment step by step by parsing the bytecode, and finally prints the results.

Through this simple example, we can see some key points of the underlying development principles of PHP7, such as compilation, parsing, execution, etc.

Conclusion:
PHP7 is a high-performance language, and its underlying development principles are very sophisticated and efficient. By in-depth understanding of the operating mechanism of the PHP7 virtual machine, we can better understand and optimize our PHP code. I hope this article can help readers better understand the underlying development principles of PHP7 and improve the performance and efficiency of PHP code.

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