来自PHP的参数列表之后的未捕获的SyntaxError：missing）

I am echoing some data from the PHP side along with a tag and here is the code

 echo '<a class="ui label" onclick="variant_desc('.$product_id.');"> '.$variant->Field1.' </a>';

Now the function that I have mentioned within the tag, when I click it throws me the

Uncaught SyntaxError: missing ) after argument list

error... BUT WHY? Where am I masking mistake?

</div>

I believe that it's caused of nested quotations. Try this instead:

echo '<a class=\"ui label\" onclick=\"variant_desc(\'.$product_id.\');\"> \'.$variant->Field1.\' </a>';