how to make a nubmer of variables based on how many inputs javascript code example

Example 1: using html forms to define javascript variables

var firstName = document.getElementsByName("firstname")[0].value;

Example 2: how to make a variable equal a specific element in javascript

//How to make a variable equal a specific element in javascript.

/*====DESCRIPTION STARTS HERE=======
Assuming you've already created an array and a variable, you simply set the
variable equal to the array, specifying the specific location of the value
it holds. Note though that when specifying the location, subtract one
number from the actual number we percieve. The reason for this is that computers
begin counting at 0.
  =====DESCRIPTION ENDS HERE========*/

//=====EXAMPLE=========
var listOfFirstNames = ["Will", "Kotori", "Grace", "James"]
var FirstName = listOfFirstNames[2] /*firstName now has the value of "Grace"
									since grace is the 2nd (or 3rd) element
									of the array*/