将php数组转换为逗号分隔数组

I am getting data from a row which are a bunch of integers and I need to comma separate them to use them for a chart.js dataset data. So I have got the array here:

if (mysqli_num_rows($result) > 0) {

  $categories = [];
  while($row = mysqli_fetch_assoc($result)) {
    $categories[] = $row;     
  }

echo json_encode($categories);

I need to turn it into json encoded string:

My array echos out as:

[{"respondent_sdo":"2","respondent_dcto":"3","respondent_ed":"5","respondent_ca":"5","respondent_dhpt":"3","respondent_irt":"6","respondent_gl":"2","respondent_il":"5"}]

To which I need the above to output as 2,3,5,5,3,6,5

var dataString= "<?php echo json_encode($categories, JSON_NUMERIC_CHECK);  ?>";
var catData = JSON.parse(dataString);


    var ctx = document.getElementById("myChart1");
    var myChart1 = new Chart(ctx, {
      type: 'radar',
        options: {
             legend: {
                display: true
             },
             tooltips: {
                enabled: false
             },
            scale: {
                ticks: {
                    beginAtZero: true,
                    stepSize: 1
                }
            }         
        },  
      data: {
        labels: ["Strategic Development and Ownership", 
                 "Driving change through others", 
                 "Exec Acumen", 
                 "Commercial Acumen", 
                 "Develops High Performance Teams", 
                 "Innovation and risk taking", 
                 "Global Leadership", 
                 "Industry Leader"
                 ],


        datasets: [{
          label: 'Ian Galbraith',
          backgroundColor: "rgba(255,6255,255,0)",
          borderColor: "lightblue",
          data: catData,
        }]
      }
    }); 

Why don't you change associative array into numeric one in PHP file like:

Instead of:

if (mysqli_num_rows($result) > 0) {

  $categories = [];
  while($row = mysqli_fetch_assoc($result)) {
    $categories[] = $row;     
  }

echo json_encode($categories);

Use:

if (mysqli_num_rows($result) > 0) {

  $categories = [];
  while($row = mysqli_fetch_assoc($result)) {
    $categories[] = $row;     
  }
$response = array();
foreach($categories as $c){
   foreach($c as $val){
      $response[] = (int)$val;
   }
}
echo json_encode($response);

I hope it helps

To achieve this you can use Object.keys to get the keys from the object and then populate an array with the values from those keys:

// Use this in production
//var arr = <?php echo json_encode($categories, JSON_NUMERIC_CHECK);  ?>;

// For this example:
var arr = [{
  "respondent_sdo": "2",
  "respondent_dcto": "3",
  "respondent_ed": "5",
  "respondent_ca": "5",
  "respondent_dhpt": "3",
  "respondent_irt": "6",
  "respondent_gl": "2",
  "respondent_il": "5"
}]

var catData = [];
Object.keys(arr[0]).forEach(function(key) {
  catData.push(parseInt(arr[0][key], 10));
});

console.log(catData);

However, I would suggest that you instead perform the logic to extract the integers in your PHP code and just provide them to the JS.

</div>

Or use array map function.

var catData = JSON.parse(dataString);
var values ='';
values += catData.map(function(a) {
    return a.foo+',';
});

values = values.replace(/,\s*$/, ""); //to remove last coma