March 2015
Beginner
768 pages
18h 32m
English
Content preview from Beginning JavaScript, 5th Edition
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AAnswers to Exercises
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 + 32Exercise 1 Solution
<!DOCTYPE html>
<html lang="en">
<head>
<title>Chapter 2: Question 1</title>
</head>
<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">
<head>
<title>Chapter 2, Question 2</title>
</head>
<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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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.