Question

function myfunction()
  {
  window.setTimeout(alert('I waited for you.'),700000000);
  }

I call a function like this and I get an immediate alert saying “I waited for you”.

I initially put in 7000 as the second argument, but kept pushing it up in case it was something besides seconds. I obviously want the function to do something else, but I broke it down to this simplistic example to prove to myself where the problem lies.

What’s my mistake?

Answer 1

You have to pass a function reference, not the result of executing alert() like this:

function myfunction() {
    window.setTimeout(function() {alert('I waited for you.')},700000000);
}

When you pass alert('I waited for you.') to setTimeout(), you’re telling the javascript interpreter to execute alert('I waited for you.') and then pass the return result to setTimeout(). Since that immediately executes the alert() statement and alert doesn’t return a function for setTimeout() to use, that is clearly not what you want.

Instead, you want to pass a function reference to setTimeout(). That can be done either with an anonymous function as in the example I provided above or it can be done with a separate named function like this:

function myAlert() {
    alert('I waited for you.');
}

function myfunction() {
    window.setTimeout(myAlert, 700000000);
}

Note: for more advanced usages, you can actually pass an immediately executed function to setTimeout() as long as that function returns a function reference that setTimeout() can call later. But, that is clearly not the usage you are attempting here with your alert()