why use ajax javascript code example

Example 1: ajax syntax in javascript

var id = empid;

$.ajax({
    type: "POST",
    url: "../Webservices/EmployeeService.asmx/GetEmployeeOrders",
    data: "{empid: " + empid + "}",
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function(result){
        alert(result.d);
        console.log(result);
    }
});

Example 2: $.ajax javascript

$.ajax({
    url: 'https://example.com/your-page',
    success:function(data){
        //'data' is the value returned.
    },
    error:function(){
        alert('An error was encountered.');
    }
});