[Solved]-Get method in php then pass the value into json format-Chart.js

your parameter is missing in ajax

$.ajax({
    url : "http://localhost:8888/ClicksChart/ckbox.php?CatId=<?php echo $_GET['CatId'];?>",
    type : "GET",
    dataType:'json',
    success : function(array){
        console.log(array);

        alert('Welcome');

You forgot to write echo

url : "http://localhost:8888/ClicksChart/ckbox.php?CatId=<?php echo $_GET['CatId'];?>",

You are missing an '=' and an 'echo'

$.ajax({
url : "http://localhost:8888/ClicksChart/ckbox.php?CatId=<?php echo $_GET["CatId"];?>",