How to loop through a fetched query in PHP using mysql - php

Question

I have a PHP class where I am initializing an array retrieved from database in the constructor:
class TableClass{
public function __construct($con, $id){
$this->con = $con;
$query = mysqli_query($this->con, "SELECT * FROM table1 WHERE id='$id'");
$this->table_result= mysqli_fetch_array($query);
}
}
I have different functions that I want to use the array without having to fetch again. I just want to loop through the results and make some calculations.
I tried the following syntax:
public function getNumberOfComments(){
for ($i = 0; $i < count($this->table_result); $i++) {
$comment= $this->table_result[$i]['comment'];
}
}
I am getting an error:
Illegal string offset "comment"
What is the correct syntax?

Answer 1

You are fetching one row from the result set:
$this->table_result= mysqli_fetch_array($query);
Assuming that the id is the primary key, you will have 0 or 1 rows in your result set, so if a row is found, you can access the fields directly without using a loop:
$comment= $this->table_result['comment'];

Answer 2

Illegal string offset "comment" is telling you that the value of $this->table_result[$i] is not an array, and therefore does not contain an element named comment.
The problem is possibly being caused by the code in the constructor failing to work properly; you don't have any error checking in there, so if it fails, it won't tell you about it.
Add some error checking in the constructor, find out why it's failing, and fix it.