How to remove the last character from last string in a While loop?-CodePudding

I am trying to insert a PHP loop with data from my mysql database inside a Google Charts script.

My result from the database looks like this:

$result = $wpdb->get_results(
    "Query");

The loop that I am trying to make is supposed to look like this

['$result',  $result],

And this is what I have come up with so far

$count = 0;
while ($count < count($result)) {
    echo "['" . $result[$count]->dato . "', " . $result[$count]->vaegt . "].<br>";
    $count  ;
    }

Which create the string that I am looking for. The problem is that I need to remove the comma from the last string in the loop.

I have tried the function LTRIM, but it removes it from every string in the loop, not just the last.

What would be the best solution to fix this problem?

CodePudding user response：

You can use json_encode, I think it will give you the kind of output you want.

Like this :

$arr = array();

foreach ( $result as $res ) {

    $dato = $res->dato;
    $vaegt = $res->vaegt;

    $arr[$dato] = $vaegt; 

}

$output = json_encode($arr);

Then pass $output to JS and use it like this :

var data = new google.visualization.DataTable("your JSON variable");

var options = {
 title:your option,
 legend:your option,
 chartArea:your option
};

var chart = new google.visualization.LineChart(document.getElementById("the ID of the HTML element in which you want to output the result"));

chart.draw(data, options);

CodePudding user response：

First off, don't use count() for a fixed result in a loop. It may look convenient, but it's slower as it performs the operation over and over on each iteration. Assign the count result to a variable first. And personally, I would use a for() loop here.

Secondly, you need to use a condition inside the loop. Rather than trying to remove the last comma just run a check on the iteration count, if it's not last then add a comma.

$count = count($result);
for($i = 1; $i <= $count; $i  )
{
    echo "....";
    if($i < $count)
    {
        echo ", ";
    }
}