如果項目計數大於4，WordPress將顯示短代碼

What @LoicTheAztec is one good solution but if you want another solution you can use the following:

WordPress have built in function which allow you to remove the default callback function for your shortcode and replaced it with your custom one.

In this case we are going to check if the cart content count is more than 4 then remove the default callback and replace it with ours .

i will consider for example that the page id which you have is 49 here which you should change when using this code to match the page which contain the shortcode.

now we need to add our custom callback to display whatever message you want:

the code above is tested and working 100%

You can add conditional shortcode by using below code :

Note : In the above question you re-declare the predefined function which is incorrect , do_shortcode() is predefined function for echo the shortcode in template file.

For more help see this link : Click Here

You can embed a shortcode in a custom shortcode with the needed conditional logic:

Code goes in function.php file of your active child theme (active theme). tested and works.
(see at the end how I have tested that).

USAGE:

1) For more than 4 items in cart (4 items is set by default in the shortcode):

[my_wheel id=\\\"1111\\\"]

1 2	[my_wheel id=\\\"1111\\\"]

2) For more than 6 items in cart for example:

[my_wheel id=\\\"1111\\\" count=\'6\']

1 2	[my_wheel id=\\\"1111\\\" count=\'6\']

How this has been tested.

As I can\'t test this shortcode that comes from a specific third party plugin, I have created a [my_wheel] shortcode that will output the ID provided in the shortcode argument id:

Code goes in function.php file of your active child theme (active theme).

Then I have added [my_wheel id=\\\"1111\\\"] shortcode in the WordPress text editor of a page and I get this display when the cart items count is 5 or more:

So it works.