what is setTimeOut() function in javascript?

Question

Can i ask what the function of setTimeOut method in javascript?As below:

function startTime()
{
var today=new Date();
var h=today.getHours();
var m=today.getMinutes();
var s=today.getSeconds();
// add a zero in front of numbers<10
m=checkTime(m);
s=checkTime(s);
document.getElementById('txt').innerHTML=h+":"+m+":"+s;
t=setTimeout('startTime()',500);
}

Solution 1

Not sure you what you want.

setTimeout is a method of the global window object. It executes the given function (or evaluates the given string) after the time given as second parameter passed.

Read more about setTimeout.

Solution 2

setTimeout() just schedules (sets a timer for) a function to execute at a later time, 500ms in this case. In your specific code, it's updating the screen with the current time every half-second (it only schedules one call, 500ms from now...but that startTime call scheduled another).

Also...passing a string to it when you can avoid it is bad practice, for your example it should be:

t = setTimeout(startTime, 500);