Should I ever place a function declaration in global object in javascript

Question

Should I ever place a function declaration or a var function expression in the global object? I see this happen a lot in tutorials, but when you would fe use function names like 'atob' or 'btoa', they would override functions of the window object. Or should I always use function expressions and place them in const/let?

An example like this would override functions of the global object and cause problems. Blur() and alert() are built-in functions, so the alert will not work.

    function blur(){
    }

    var alert = function(){
      console.log("Bye")
    }

    alert("Hi");``` 

Answer 1

The way I handle this is I always prefix my function names with "jellyBelly":

function jellyBellyBlur(){
}

var jellyBellyAlert = function(){
  console.log("Bye")
}

jellyBellyAlert("Hi");``` 

So, far, I've had no naming conflicts. I'm a professional.