<TITLE>Java Script input string and convert to integer and float</A></TITLE>


/*This script will input a float and then add the numbers*/

var sum = 0, howmany=0;
var numstring = null;//declaring and setting a string to the null string.

numstring = prompt ("Find the sum of the first what natural numbers?","");//inputting a string.
howmany = parseInt(numstring);

for (var i = 1; i <= numstring; i++)
  sum += i;

alert("The sum of the first " +howmany+ " natural numbers is " +sum);


Run Script