PHP Global Variables: Best Practices

When defining global variables in PHP, it is important to keep in mind the following points:

1. To use the global keyword: When using a global variable inside a function, it is necessary to declare the variable as global using the global keyword. Otherwise, PHP will consider it as a local variable.
2. Avoid overusing global variables: Global variables can easily lead to variable pollution and naming conflicts, so it is best to minimize their usage in the program.
3. Naming conventions: Global variables should have clear and meaningful names that follow a standardized format, making it easier for other developers to understand and maintain the code.
4. Safety consideration: Global variables may be tampered with by untrusted users, so it is important to handle the values of global variables carefully to avoid security vulnerabilities.
5. Substitute global variables with constants: If a variable’s value will not be changed, consider using a constant instead of a global variable to improve the readability and security of the code.