Question

i want to show numbers one by one after a second, but below coding shows the whole numbers together.

function showVal(){
    for(i=0; i<5; i++)
    {
        var showingVal= document.write("the number is "+i);
        document.write("<br />");       
    }
}
setInterval('showVal()',1000);

Answer 1

It’s better to use setTimeout instead.

function showVal(n) {
  if(!n)
    n = 0;
  var showingVal = document.write("the number is " + n);
  document.write("<br />");       

  if(n < 4) {
    setTimeout(function() { showVal(n + 1); }, 1000);
  }
}

setTimeout(showVal, 1000);

Demo: http://jsbin.com/avunif

It’s better than setInterval because after you printed 5 numbers, your tick handler won’t be called. Efficiency. Plus no global variables. 🙂

Or you can clearInterval instead.