Why is the method executed immediately when I use setTimeout?

Question

I'm trying to write a simple code with a setTimeout, but the setTimeout just won't wait the time it's supposes to and the code execute immediately. What am I doing wrong?

setTimeout(testfunction(), 2000); 

Answer 1

You're calling the function immediately and scheduling its return value.

Use:

setTimeout(testFunction, 2000);                        ^ 

Notice: no parens.

Answer 2

Remove the parenthesis

setTimeout(testfunction(), 2000); 

If you want to send parameters to the function, you can create an anonymous function which will then call your desired function.

setTimeout(function() {      testfunction('hello');  }, 2000); 

Edit

Someone suggested to send a string as the first parameter of setTimeout. I would suggest not to follow this and never send a string as a setTimeout first parameter, cause the eval function will be used. This is bad practice and should be avoided if possible.