CODEWITHSUNDEEP
javascriptsettimeout
TecBrat
TecBrat

Reputation: 3719

javascript setTimeout not doing what I expect

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?

Upvotes: 1

Views: 116

Answers (6)

jfriend00
jfriend00

Reputation: 707158

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()

Upvotes: 3

TecBrat
TecBrat

Reputation: 3719

I found out that if I put quotes around the first argument, it works. Here's what I actually did:

function divhide()
  {
  window.setTimeout("realhide()",7000);
  }

function realhide(){
  var mydiv = document.getElementById("mydiv");
  mydiv.style.display="none";
  mydiv.innerHTML="";
}

Upvotes: -2

anothershrubery
anothershrubery

Reputation: 20993

You can simply wrap the alert('I waited for you.') in quotes " as such:

function myfunction() 
  { 
  window.setTimeout("alert('I waited for you.')",7000); 
  }

The number is the amount of milliseconds to wait, so 7000 is 7 seconds.

See http://jsfiddle.net/Ac5Xf/

Upvotes: -1

j08691
j08691

Reputation: 207861

Wrap it in an anonymous function like:

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

Here's an example jsFiddle (with a more manageable 3 second delay).

Upvotes: 2

Nicola Peluchetti
Nicola Peluchetti

Reputation: 76870

You should do

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

window.setTimeout(makeAlert,700000000);

otherwise the alert() is executed immediatly

Upvotes: 2

Sirko
Sirko

Reputation: 74036

try this

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

In your code the function alert is called immediately. If you want to have a later execution you should pass a reference to a function and not a call of a function to setTimeout.

Upvotes: 2

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