settimeout = setinterval with delay?

Quick question regarding settimeou开发者_Python百科t, does it execute periodically like setinterval?

Say I have a line that goes like setTimeout("functionx();" , 1000) , is functionx() executed only once (after 1 second)? or does it go like this:

1. 1 sec delay
2. run functionx()
3. execute functionx every 1 second after that?

thanks

setTimeout is a one-off, the function you give it is called only once.

(Off-topic: Note that you almost never want to give either setTimeout or setInterval a string containing code; instead, give it an actual function reference.)

So this will call the function foo once, after half a second or so (these things are not precise):

function foo() {
    display("Hi there");
}
setTimeout(foo, 500);

...whereas this will keep calling it every half second or so until you stop it:

var timer = setInterval(foo, 500);
// Somewhere else, stop it:
clearInterval(timer);

With setTimeout(), the function will be executed only once, after the specified delay.

That single execution is precisely the difference with setInterval(), which calls the function repeatedly.

setTimeout will execute the given function after the given milliseconds. setInterval will execute the given function every given milliseconds. If you want setTimeout to act like setInterval, you'll have to make the function you specified recursive.