HOMEWORK 4

Chapters 18,19,(20),12,13

1) Define the following terms:

a. variable

b. event handler

c. Trojan program

d. privacy

e. virus

f. cookies

g. encryption

h. random numbers

2) Discuss what a user can do to make a personal computer more secure.

3) You have a variable called credits that holds the number of credits that a student has. Write a JavaScript statement that alerts the user if he/she should apply for graduation by checking if credits is more than 100.

4) Trace the following JavaScript code. At each line show what is in the variables by filling in the chart below:

a. var cost = 0;

b. var taxRate = .08;

c. var present = "videogame";

d. if (present == "sweater")

e. cost = 15;

f. else if (present == "watch")

g. cost = 30;

h. else if (present == "videogame")

i. cost = 100;

j. cost = cost + cost * taxRate;

k. present = “none”;

Line number	cost	present	taxRate
a
b
c
d
e
f
g
h
i
j
k

5) What would occur if you changed line h above to (notice the capital ‘V’ in the word Videogame):

if (present == "VideoGame")?

6) What is the dot operator in JavaScript (object.property)? Give an example of when it might be used.