字符串中有运算符（"5*8+3"）这样的字符串，该怎么计算（5*8+3）

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var n = '5*8+3';
        //怎样操作才能计算出字符串中的表达式并输出到控制台？
    </script>
</body>
</html>

采用eval(expr)，如果可用请采纳谢谢


 < SCRIPT  LANGUAGE ="JavaScript" >
var n = '5*8+3';
alert(eval(n));
 </ SCRIPT >


<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var n = '5*8+3';
        console.log(eval(n))
    </script>
</body>
</html>