javascript - Shuffle function not working on click button -

i trying create memory card game using vanilla js. have shuffle function call on reset game button it's not working.

this have far:

var imagelist = [         {             name: 'image_1',             id: 1         },         {             name: 'image_2',             id: 2         },         {             name: 'image_3',             id: 3         },         {             name: 'image_4',             id: 4         }     ],     card = [],     appendtoboard = document.getelementbyid('cardtable');  function shuffle(array) {   //some code here }  function createcarddeck() {     shuffle(imagelist); // calling shuffle(imagelist)    //some code here  } 

all above works when call shuffle(imagelist) on btnreset nothing

document.getelementbyid('btnreset').addeventlistener('click', function(event) {     event.preventdefault();     shuffle(imagelist); }, true); 

https://jsfiddle.net/rmbor/qnzaope7/

any suggestions appreciated.

do 2 things:

1. add var card = ''; createcarddeck function clear before adding markup:

   function createcarddeck() {     shuffle(imagelist);     var card = '';     (var = 0; < imagelist.length; i++) {...} } 

2. replace shuffle(imagelist) createcarddeck() in addeventlistener function:

   document.getelementbyid('btnreset').addeventlistener('click', function(event) {     event.preventdefault();     createcarddeck(); }, true); 

check demo - fiddle.