Ajax hide hidden problem solution_Basic knowledge

There are two tables on my page. After calling ajax, I hide one table and then use HTML to create another table. As a result, the top of the new table has undefined. What causes this and how to solve it? The detailed code is as follows:

Copy code The code is as follows:

Enter name search:

Copy code The code is as follows:

---

Select	Region code	Country name
	${list[0] }	${list[1] }

---

is a certain section of code in the above code. Syntax error, the following is the modified code segment:
success: function(json) {
var tableHTML = ”;
…