PHP array not updating

Question

There is probably something dumb I am doing wrong here.

public function get_scores($id)
{
    $results = array();
    $sql = "SELECT * FROM scores WHERE comp_id = $id";
    $rows = $this->db->query($sql)->result();
    foreach($rows as $row) {
        if($row->confirmed_id) {
            $results[$row->uid] += $row->score;
        }
    }
    sort($results);
    return $results;
}

So basically what I am trying to do is add all of the users scores in the database and return them in order of rank. confirmed->id is just a check to make sure the score has been confirmed (and thus is addable to their total score). I am basically trying to just make an associative array where the key is the users ID, and the score of each question they have in the database is added on. The query works fine, and $row-uid and $row->score both return the correct thing for every row, but $results[] never has anything added to it. If I even change it just to something silly like $results[3] = 0 at top, and then $results[3]++ or += 1 in the for loop, it doesn't add anything to $results[3].

EDIT: Problem solved. Indeed was something dumb -- confirmed_id was set to null by my partner when he reran our database after I had previously set it all to 1. Thanks guys :)

Can you just check without '+' ie. $results[$row->uid] = $row->score; — Duke
– Duke, Commented Mar 22, 2012 at 4:31
What is the value of $row->confirmed_id for each row? Is it ever truthy? — cHao
– cHao, Commented Mar 22, 2012 at 4:32
You have something against curly braces or using aggregate SQL functions? Your code could benefit from both :) — Jason McCreary
– Jason McCreary, Commented Mar 22, 2012 at 4:33
Sigh. Embarrassing. My coding partner set them all to NULL in our database for some reason. After I had all set them to 1. What a dumb problem. — Paul
– Paul, Commented Mar 22, 2012 at 4:44

Mark Fraser · Accepted Answer · 2012-03-22 04:37:06Z

2

You are adding to $results[something] before it exists. You need to create it in the first case and then only increment it once it exists.

answered Mar 22, 2012 at 4:37

Mark Fraser

3,1982 gold badges32 silver badges48 bronze badges

Sign up to request clarification or add additional context in comments.

8 Comments

Mark Fraser Over a year ago

Well it is at least a problem.

Paul Over a year ago

This isn't -- I have added in $results[3] = 0 at the top, and it doesn't fix it previously. [3] is my test case that all current uids are.

Mark Fraser Over a year ago

I think you misunderstand. Initially $results[anyid] is undefined. It doesn't exist. Thus when you do $results[anyid] += 3, you are doing $results[anyid] = undefined + 3. Which won't do what you want.

Paul Over a year ago

Right -- which is why I was saying at the top of my code I was setting it $result[3] to 0, since I know all of my current id's are 3 anyway. So it would be doing $result[3] = 0 + x. Thanks though =]

Mark Fraser Over a year ago

The fact remains that the code you posted has a blatant defect. So since you keep insisting it isn't wrong I'm downvoting the question until you fix it.

|

Thilanka · Accepted Answer · 2012-03-22 04:46:58Z

0

You need to remove the "+=" operation from the code. Check with this.

public function get_scores($id)
{
    $results = array();
    $sql = "SELECT * FROM scores WHERE comp_id = $id";
    $rows = $this->db->query($sql)->result();
    foreach($rows as $row)
        if($row->confirmed_id)
            $results[$row->uid] = $row->score;
    sort($results);
    return $results;
}

Your previous operation is similar to

$results[$row->uid] = $results[$row->uid] + $row->score;

So it will not add values to your row.

answered Mar 22, 2012 at 4:46

Thilanka

1,7637 gold badges22 silver badges36 bronze badges

Collectives™ on Stack Overflow

PHP array not updating

2 Answers 2

8 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

8 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related