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This appendix provides the answers to the questions you find at the end of each chapter in this book.

CHAPTER 2

Exercise 1 Question

Write a JavaScript program to convert degrees centigrade into degrees Fahrenheit, and to write the result to the page in a descriptive sentence. The JavaScript equation for Fahrenheit to centigrade is as follows:

``degFahren = 9 / 5 * degCent + 32``

Exercise 1 Solution

``````<!DOCTYPE html>

<html lang="en">
<title>Chapter 2: Question 1</title>
<body>
<script>
var degCent = prompt("Enter the degrees in centigrade", 0);
var degFahren = 9 / 5 * degCent + 32;

document.write(degCent + " degrees centigrade is " + degFahren +
" degrees Fahrenheit");
</script>
</body>
</html>``````

Save this as `ch2_question1.html`.

Exercise 2 Question

The following code uses the `prompt()` function to get two numbers from the user. It then adds those two numbers and writes the result to the page:

``````<!DOCTYPE html>

<html lang="en">
<title>Chapter 2, Question 2</title>
<body>

<script>
var firstNumber = prompt("Enter the first number","");
var secondNumber = prompt("Enter the second number","");
var theTotal = firstNumber + secondNumber;

document.write(firstNumber + " added to " + secondNumber +
" equals " + theTotal);
</script>
</body>
</html>``````

However, if you try out the code, you’ll discover that it doesn’t work. Why not? Change the code so that it does work.

Exercise 2 Solution

The data that the `prompt()` actually obtains is a string. ...

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