Exercises and Challenges - Learning C# by Programming Games - page 392

A.2 Exercises and Challenges for Part II
Exercises
1. Keywords
(a) What does the word void mean, and when do we need this keyword?
(b) What does the word int mean, and when do we need this keyword?
(c) What does the word return mean in a C# instruction, and when do we need
it?
(d) What does the word this mean in a C# instruction, and when do we need it?
In what kind of method can we not use this word?
2. Type conversions
Suppose that the following declarations have been made:
int x;
string s;
double d;
Expand the following assignments with the necessary type conversions (assum-
ing that the string indeed represents a number):
x=d;
x=s;
s=x;
s=d;
d=x;
d=s;
3. Methods with a result
(a) Write a method RemainderAfterDivision with two parameters x and y , which
returns the value of x%y , without using the % operator.
(b) Write a method Circumference that gives as a result the circumference of a
rectangle, whose width and height are given as parameters.
(c) Write a method Diagonal that gives as a result the length of the diagonal of a
rectangle, whose width and height are given as parameters.
(d) Write a method ThreeTimes , that returns three concatenated copies of a string
passed as a parameter. So, ThreeTimes("hurray!") should result in the string
"hurray!hurray!hurray!" .
(e) Write a method SixtyTimes . that returns sixty concatenated copies of a string
passed as a parameter. Try to limit the number of instructions in that method.
(f) Write a method ManyTimes . that returns a number of concatenated copies of a
string passed as a parameter, where that number is also passed as a parameter
(you may assume that this number is 0 or larger). So, ManyTimes("what?", 4)
should result in "what?what?what?what?" .