How does PHP handle memory allocation when using include versus defining functions?

When using the include function in PHP, the code from the included file is executed in the same memory space as the calling script, which can lead to memory bloat if the included file contains a lot of code. To handle memory allocation more efficiently, it is recommended to define functions in separate files and include them only when needed. This way, the functions are loaded into memory only when they are called, reducing memory usage.

// Define functions in separate files
// function1.php
function function1() {
    // function code here
}

// function2.php
function function2() {
    // function code here
}

// Include functions only when needed
include 'function1.php';
include 'function2.php';

// Call the functions when needed
function1();
function2();