The JavaScript function that treats a string as executable
code is named eval(), not exec().

eval("console.log(\"hellllooo\")");

does the same thing as

console.log("hellllooo");

As I said, it is needed for implementing JSON.parse(), but
is virtually never needed for normal applications. And it
should be avoided for security reasons: "eval is evil" is
the byline of the developer of JSON, Douglas Crocker of Yahoo.

I'm still not sure exactly what will be happening on
Thursday ...

Dr. Vickery