Php – How to hide a value on x axis chartjs

I believe you want the X-axis to show the ticks with stepSize=5, but want to hide those 5, 15, 25, etc.

For chartjs, to do what you want, you can specify the ticks with callback like the following:

   ticks: {
             stepSize: 5, 
             callback: function(value, index, values) {
             return getCategoryLabel(value);
             }
           }

and then use the following callback function (I have used remainder (%) to do the calculation), for your case, the if condition statement can be if (value %5 ==0 && value %10 !=0) {....} else {....} :

  function getCategoryLabel(value) {
            if ( value %5 ==0 && value %10 !=0 ) {
                return '';
            } else {
                return value;
            }
        }

So the complete code (Scatter example) will be like:

<div>
  <canvas id="myChart"></canvas>
</div>

<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>


<script>
        const canvas = document.getElementById('myChart');
        const ctx = canvas.getContext('2d');

        
        var chartData = {}; 

        var myChart = new Chart(ctx, {
            type: 'scatter', 
          data: {
            datasets: [{
              label: 'Test Scatter',

              data: [
              {x: 27,y: 6}, 
              {x: 25, y: 12}, 
              {x: 26,y: 5}, 
              {x: 24, y: 10}, 
              {x: 28,y: 7}, 
              {x: 29, y: 7}, 
              {x: 26,y: 6}, 
              {x: 24, y: 10}, 
              {x: 11,y: 3}, 
              {x: 18, y: 5}, 
              {x: 0,y: 10}, 
              {x: 10, y: 5}, 
              {x: 0.5,y: 5.5}],
               
               backgroundColor: ['red'], 
               borderWidth: 1
                }],
                
            },
            options: {
                scales: {

                    x: {
                       type: 'linear',
                       position: 'bottom',

                    ticks: {
                            stepSize: 5, 
                            callback: function(value, index, values) {
                                return getCategoryLabel(value);
                            }
                        }

                        },

                    y: {
                        beginAtZero: true,
                      
                    }

                },
                responsive: true, 
                maintainAspectRatio: true 
            }
        });

        function getCategoryLabel(value) {
            if ( value %5 ==0 && value %10 !=0 ) {
                return '';
            } else {
                return value;
            }
        }

        function updateChart(newData) {
            myChart.data.datasets[0].data = newData.allData;
            myChart.update();
        }


    </script>

See result here:

Note: If you want to hide 5, 15, 25 on Y-axis instead, then put the ticks block inside the scales > y