Question

I am trying to use polling for a small check that is performed at an interval of 15 secs.

setInterval(function(){
            $.ajax({ url: "aaa.com",
                success: function(data){
                showUpdate(data);
              }, dataType: "text"});
            }, 15000);

But this means that there is an initial delay of 15 secs, before the polling starts, which is not desired in my case.
How can i force the polling to start immediately?

Answer 1

Don’t look for smart solutions when simple ones do the job :

function check() {
   $.ajax({ url: "aaa.com",
     success: function(data){
     showUpdate(data);
   }, dataType: "text"});
}
check();
setInterval(check, 15000);

Alternatively, I’d generally prefer

function check() {
   $.ajax({ url: "aaa.com",
     success: function(data){
        showUpdate(data);
        setTimeout(check, 15000);
   }, dataType: "text"});  
}
check();

Because there wouldn’t be a stack of calls in case of delayed response.