Use Line Break in Document. Write() Output

use this

 function FahToCent (degFah)
{
    return 5/9 * (degFah - 32);;
}

var degFah = new Array ();
for (var loopCounter = 0; loopCounter <= 2; loopCounter++)
{
    degFah[loopCounter] = prompt ("Enter Temperature in Fahrenheit");
    document.write(FahToCent (degFah[loopCounter])+"<br>");   
}

Example Link :

just add break tag in your function FahtoCent

 degCent[loopCounter] = 5/9 * (degFah[loopCounter] - 32)+"<BR>";

You've defined degCent as an Array, which is passed to document.write() as an argument. This argument is supposed to be a string, and now it's an array. Hence it's automatically converted to a string before outputting, using Array.toString() method. This method returns a comma-separated list of array values (as a string).

However, you can convert the returned array to a string, and add linebreaks with the same manouver, using an Array-method called join(). Like this:

document.write(FahToCent(degFah).join('<br/>'));

However, document.write() is considered as a bad practise for DOM manipulations. Please check some advanced methods to show the output in the document:

MDN: innerHTML, MDN: appendChild()

I'm not altogether certain of what you are asking here but I think you just want to go to a new line after the code runs. In which case you need writeline rather than write and remove "br" tag

document.writeline (FahToCent (degFah));