Using wc_get_product() with a PHP variable for product ID

Update related to your recent comment. The 2 ways to explore:

1) Instead of you should try to use to get the product object (avoiding the error):

$courseID = the_field('course_id');// Optionally try this (uncommenting)// $courseID = (int)$courseID;// Get an instance of the product object$_product = new WC_Product($courseID);

2) Alternatively if this doesn't work, you should try to use get_post_meta() function to get the product price (or any product meta data) this way:

<?php //Gets the course ID from the custom field entered by user$courseID = the_field('course_id');// Get the product price (from this course ID):$course_price = get_post_meta($courseID, '_regular_price', true); // Output the Course price?>  <span class="coursePrice">$<?php echo $course_price;?></span>

This time you should get displayed the price with one or the other solutions.

Update: May be Also you need to convert $courseID to an integer variable.

Because you need to use your variable $courseID inside wc_get_product() (without the 2 ') function this way:

<?php //Gets the course ID from the custom field entered by user$courseID = the_field('course_id');// Optionally try this (uncommenting)// $courseID = (int)$courseID;// Here$_product = wc_get_product( $courseID );$course_price = $_product->get_regular_price();// Output the Course price?>  <span class="coursePrice">$<?php echo $course_price;?></span>

This should work now.

You can try this out :

$courseID = the_field('course_id');$product = get_product( $courseID );

I figured out the answer after running through the possible solution routes that @LoicTheAztec supplied in his response. None of these worked and so I assumed something else was up.

I use Advanced Custom Fields to add custom fields in the back end and I was using ACF's the_field() in order to create my variable. That is incorrect usage of that function as it's designed to display the field, (it's basically using php's echo). To work with these custom field's you need to use ACf's get_field() which is to use it to store a value, echo a value and interact with a value.

Once I switched to setting my $courseID to this..

$courseID = get_field('course_id'); 

Everything worked. My code worked, and all @LoicTheAztec's code approaches also worked.