<!DOCTYPE html>
<html>
    <head>
        <meta charset=utf-8>
    </head>
    <body>
        <script type="text/javascript">
        	// 补全代码
        	Number.prototype._isPrime = function(){
                let num = Number(this);
                let count =0;
                if(num > 1){
                    for(let i =2;i<num;i++){
                        if(num % i ==0){
                            count++;
                        }
                    }
                    if(count != 0){
                        return false;
                    }else{
                        return true;
                    }
                }
            }
        </script>
    </body>
</html>