Compare variable against previous variable in a while loop PHP

Question

I have a while loop where I want to compare the current variable ($high) to the previous one. If the value is higher I want to show a green background and if it is lower I want to show a red background.

At the moment, if the value is higher, then it shows a red background, also it only seems to compare the latest result and not all of the values in the loop.

Link to test page

$previous = 0;
while ($row =mysql_fetch_assoc($result)){
    $high = $row['High'];
    if ($high > $previous){
        ?> <span style="background:green"><?php echo $row['High']; ?></span><?PHP
    }else{
        ?> <span style="background:red"><?php echo $row['High']; ?></span><? PHP
    }
    $previous = row;
}

1.mysql_* is deprecated and removed library now, so upgrade yourself to PHP7 along with mysqli_* or PDO. 2. $previous = row; needs to be $previous = $high; — Death-is-the-real-truth
– Death-is-the-real-truth, Commented Sep 17, 2018 at 10:48
you are assigning the entire $row dataset to $previous, which will be an array, and that will be used to compare instead of the actual value of $row['High']; — noid
– noid, Commented Sep 17, 2018 at 10:54

Death-is-the-real-truth · Accepted Answer · 2021-10-11 04:31:21Z

1

mysql_* is deprecated and removed library now, so upgrade yourself to PHP7 along with mysqli_* or PDO libraries.

$previous = row; needs to be $previous = $high;

Output:-https://eval.in/1058293

edited Oct 11, 2021 at 4:31

answered Sep 17, 2018 at 10:56

Death-is-the-real-truth

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Comments

Barry · Accepted Answer · 2018-09-17 10:55:40Z

1

At present the code stores the previous $row, not he specific $row['High']. Please change

$previous = $row;

to

$previous = $row['High'];

answered Sep 17, 2018 at 10:55

Barry

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1 Comment

Alex Shesterov Over a year ago

Or even $previous = $high;

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