how to upload png,jpg extexsion images in files with ajax code example

Example 1: ajax file upload jquery

$('#upload').on('click', function() {
    var file_data = $('#sortpicture').prop('files')[0];   
    var form_data = new FormData();                  
    form_data.append('file', file_data);
    alert(form_data);                             
    $.ajax({
        url: 'upload.php', // point to server-side PHP script 
        dataType: 'text',  // what to expect back from the PHP script, if anything
        cache: false,
        contentType: false,
        processData: false,
        data: form_data,                         
        type: 'post',
        success: function(php_script_response){
            alert(php_script_response); // display response from the PHP script, if any
        }
     });
});

Example 2: Upload image via ajax (jquery)

var form = new FormData();
form.append('varName','data');
$.ajax({
  type:'POST',
  url: $(this).attr('action'),
  data:formData,
  cache:false,
  contentType: false,
  processData: false,
  success:function(data){
    //function here
  },
  error: function(data){
    //function here
  }
});