PROBLEM WITH CHAPTER 4, EXERCISE 3
I am having a problem getting Exercise 3 from chapter 4 of the book to work. At first, I tried to solve the problem on my own and could not. Finally, I resorted to the code in Appendix A and studied it very carefully to see if I understood it. I am still struggling to grasp its logic, but basically understand it.
I then entered the code from Appendix A, p. 665. With very minor deviation from what appears in the text, here is my code:
CODE FOR fix(fixNumber, decimalPlaces) FUNCTION
=====================================
<script type="text/javascript">
/* fix() Function
================================================== ===================
This function takes input of a number and requested number of decimal
places from a user in two separate prompt boxes.
It then calculates what and how many decimal places to display on
the number entered by the user.
================================================== ====================
*/
function fix(fixNumber, decimalPlaces) {
// Declare and initialize variable to hold the exponential value of
// decimal places for the number entered by the user.
var div = Math.pow(fixNumber, decimalPlaces);
// Declare String object used for searching position of decimal place.
fixNumber = new String(Math.round(fixNumber * div) / div);
// Search new String object for position of decimal place.
if (fixNumber.lastIndexOf(".") == 1) {
fixNumber = fixNumber + "."; // If no decimal places, add only
// decimal point to string.
} // end if
// Determine zeroes required.
var zeroesRequired = decimalPlaces 
( fixNumber.length  fixNumber.lastIndexOf(".")  1 )
for (; zeroesRequired > 0; zeroesRequired) {
fixNumber = fixNumber + "0";
} // end for
return fixNumber; // Returns value of fixNumber to calling function.
} // end fix(fixNumber, decimalPlaces)
</script>
CODE FOR SCRIPT WITHIN HTML BODY
============================
<script type="text/javascript">
// Prompt for user to enter a number.
var number1 = prompt("Enter a number with decimal places whose number of decimal places\nyou wish to fix: ", "");
var number2 = prompt("How many decimal places do you want?", "");
// Now print value to browser window.
document.write(number1 + " fixed to " + number2 + " decimal places is: ");
document.write( fix(number1, number2) );
</script>
A sample run of the web page where number1 = 2.10246 and number2 = 3 produced the following output in every browser I tested:
2.10246 fixed to 3 decimal places is: 2.1520223122955024
The expected result, according to the book, is 2.100. No matter what I do so far, I cannot produce this result.
Any insight or suggestions would be greatly appreciated.
Sincerely,
Robert Hieger
