How to change number of columns in Woocommerce?

in functions.php of the child theme, add:

add_filter( 'storefront_loop_columns', function() { return 4; } ); //change shop colunns//

in style.css of the child theme, add (for example):

/*adjustment for 4 shop columns*/
@media (min-width:768px){
	.site-main ul.products li.product {
		width: 22%;
		margin-right:4%;
	}
}

Hi Michael,

thanks for taking the time to reply.

I’ve tried the above code (I added the PHP first to my child theme file), but an error came up and my site was no longer accessible.

The error message said:

Parse error: syntax error, unexpected ‘?>’

Just to confirm, before I added the above code, my child theme functions file was empty except for the opening and closing tags:

<?php

?>

I hope someone can help me with this, because I’ve spent two days now trying to resolve this issue ??

if you start with an empty functions.php file in the child theme, the total added code (the total code in the file) should be:

<?php
add_filter( 'storefront_loop_columns', function() { return 4; } ); //change shop colunns//

there is no need to add the closing php tag:

?>

make sure to have absolutely no characters before the first line with the opening tag
<?php