How can PHP developers prevent issues with special characters when using numeric HTML entities in their code?

Special characters can cause issues when using numeric HTML entities in PHP code because they may not be properly encoded or decoded. To prevent problems with special characters, PHP developers can use the `htmlspecialchars()` function to encode special characters before outputting them in HTML. This function will convert special characters like `<`, `>`, `&`, `"`, and `'` to their corresponding HTML entities, ensuring that they are displayed correctly in the browser.

$special_string = "This is a special string with < and > characters.";
echo htmlspecialchars($special_string, ENT_QUOTES, 'UTF-8');