How can PHP developers ensure that their code is modular and avoids conflicts with external libraries or frameworks when including files with similar class or function names?

To ensure that PHP code is modular and avoids conflicts with external libraries or frameworks when including files with similar class or function names, developers can use namespaces to encapsulate their code and prevent naming collisions. By defining namespaces for their classes and functions, developers can organize their code into logical units and avoid conflicts with external code.

// Define a namespace for your code
namespace MyNamespace;

// Define a class within the namespace
class MyClass {
    // Class implementation
}

// Use the class within the namespace
$myObject = new MyNamespace\MyClass();