`$(".btn_shuffle").click(function () {
        var cardNumbers = [];
        $('.card').each(function () {
            cardNumbers.push(this.innerHTML);
        });
        var theLength = cardNumbers.length-1;
        var toSwap ;
        var temp;
        console.log(cardNumbers);
        for(i=theLength; i>0; i--){
            toSwap = Math.floor(Math.random()*i);
            temp = cardNumbers[i];
            cardNumbers[i] = cardNumbers[toSwap];
            cardNumbers[toSwap]=temp;
        }
        console.log(cardNumbers);

    });`