Proper Method for Hiding a Div Using PHP

Hiding a div based on an if statement is a common technique in web development. While the method you mentioned using an echo statement to add a display: none style to the div's CSS is functional, there are more appropriate methods that may be preferred.

The primary concern with using echo within CSS is that it's not considered a "proper" technique in web development. It can lead to code that is difficult to maintain and debug in the long run.

Using PHP in HTML:

A better approach is to use PHP within the HTML code to conditionally render the div. For example:

    
        

           Foo bar
        
    

With this code, the div block will only appear if the condition is true.

Adding Inline Style using PHP:

If you prefer to add an inline style to the div, you can do so like this:

    
>
       Foo bar
    

This code will add the style="display: none" attribute to the div element if the condition is true.

Note on Browser Caching:

The concern you raised about browser caching is valid. However, it's unlikely that browsers will cache the echo-ed out CSS style because it's considered dynamic content. Nonetheless, it's always best practice to test your code in different browsers to ensure it works as intended.