Multiple Choice Questions

https://csci-1301.github.io/about#authors

May 22, 2024 (01:30:37 PM)

Why are the instructors sharing most of the material in odt, docx, pdf, html and md?
- To insure compatibility across operating systems (Android, Linux, Windows, MacOs, …).
- To make it easier to access the resources in multiple ways (print, screen, etc.)
- All of the above.
What does “free” software means?
- That the software has no value.
- That the users can run the software for any purpose and study its source code.
- That it is not developed by a company.
- That the software can be downloaded at no cost.
In your IDE, the shortcut to compile your program is usually…
- “Build your solution”, ctrl + shift + B or Cmd + B
- “Save”, ctrl + S or Cmd + S
- “Exit”, alt + F4 or Cmd + q
- “Start without debugging”, Ctrl + F5 or Cmd + F5
To share or backup a project, you need to…
- share the .sln file.
- share the .cs file.
- share the .csproj file.
- zip the folder containing the .sln file and another folder with multiple files and folders in it.
If your IDE returns the message
```
Program.cs(21,21): Error CS0117: 'Console' does not contain a definition for 'WiteLine' (CS0117) (Solution)
```
This means that…
- That you misspelled the word “WriteLine”.
- Your program successfully compiled and is ready to be executed.
- That the “Console” class does not exist.
- Your IDE was not properly installed and you should reboot your computer.
Consider the following code:
```
int age, defaultChoice = 0;
decimal averagePrice;
```
Which of the following is correct?
- It contains declaration and initialization statements.
- It declares variables of two different datatypes.
- Only the value of defaultChoice is set.
- All of the above.
Consider the following code:
```
int person = 12;
int pie = 5;
int piePerPerson = pie / person;
Console.WriteLine("Each guest gets " + piePerPerson + " pie(s).");
```
What will be displayed by it?
- Nothing: an error will prevent from compiling it successfully.
- “Each guest gets 2.4 pie(s).”
- “Each guest gets 0.41666666666666666666666…” (it will never ends, displaying 6 forever).
- “Each guest gets 0.416666666666667 pie(s).”
- “Each guest gets 0 pie(s).”
Consider the following statement:
```
decimal balance = 2.5M;
decimal price = 12;
decimal remainingBalance = balance - price;
```
Which of the following is correct?
- This program will not compile because the result of balance - price is not a decimal.
- This program will not compile because a decimal cannot be negative.
- This program will compile.
- This program will not compile because you cannot store an integer value (12) in a decimal.
The method used to read a string from the user is called…
- ReadString
- ReadFrom
- ReadLine
- ReadInput
Consider the following program:
```
Console.WriteLine("Enter your age.");
string fromUser = Console.ReadLine();
int age = _______ (fromUser);
```
To correctly be able to store the string in fromUser into age, you should replace _______ with…
- (int)
- int.Parse
- Nothing: as long as the user enters an integer value, we can store it into age just fine.
- None of the above.
What are, respectively, the return types of a constructor and of a ToString method?
- Constructors do not have a return type, and a ToString method returns a string.
- Constructors and ToString methods both return strings.
- Constructors returns a string, and a ToString method does not return anything (it simply displays a text).
- It is impossible to know ahead of time, as this depends of the class they are implemented in.
What is the name of a constructor method?
- Nothing: an error will prevent from compiling it successfully.
- Whatever the name of the class is.
- It does not have any.
- The name of the instance it creates.
- Constructor
What are the three logical connectives in C# (that we studied)?
- And (&&), or (||) and negation (!).
- Equality (==), greater than (>) and less than (<).
- And (and), or (or) and negation (not).
Which of the following will evaluate to true?
- 3 > 1 && 2
- (3 > 1) && 1 != 0
- !(3 > 1)
- 3 > 1 || 2
Will the following expression evaluates, and if so, what will it evaluate to?
```
true == false || 2 / 1 > 0 && 3 - 1 != 2 * 0.5 + 0.5
```
evaluates?
- It will evaluate to a number.
- It will evaluate to false.
- It will evaluate to true.
- It will not evaluate.
- None of the above.
What will be displayed by the following code?
```
int number = 10;
while (number <= 15)
{
    number+=2;
    Console.Write(number + " ");
}
```
- 12 14 16
- 10 11 12 13 14 15
- 10 11 12 13 14
- 10 12 16
- 10 12
- 10 12 14
- 12+14+16
- 10+11+12+13+14+15
What will be displayed by the following code?
```
int i = 0;
while(i < 10)
{
    Console.WriteLine(i);
}
```
- 0 followed by a new line, forever.
- 0 1 2 3 4 5 6 7 8 9
- 0 1 2 3 4 5 6 7 8 9 with a new line between each number
- Nothing
Consider the following code:
```
Console.WriteLine("Enter… something!");
int answer;
bool valid = int.TryParse(Console.ReadLine(), out answer);
Console.WriteLine($"returns: {valid}, value:{answer}");
```
If the user enters “Train”, then it will display:
- returns: False, value: 0
- returns: True, value: 0
- returns: True, value: Train
- returns: False, value: Train
- Nothing: the program will crash.

Consider the following code:

string answer;
Console.WriteLine("Enter something");
answer = Console.ReadLine();
while (answer != "yes" || answer !="Yes"){
    Console.WriteLine("Enter something");
    answer = Console.ReadLine();
}

What can the user enters to exit this loop:

There is nothing the user can enter to exit this loop
Either “Yes” or “yes”
Anything that is different from “Yes” and “yes”
Anything

Consider the following code:
```
int answer;
Console.WriteLine("Enter something");
answer = int.Parse(Console.ReadLine());
while (answer > 10 && answer < 100){
    Console.WriteLine("Enter something");
    answer = int.Parse(Console.ReadLine());
}
```
What can the user enters to exit this loop?
- Any number not between 10 and 100 (both included)
- Any number between 10 and 100 (both included)
- Any number between 10 and 100 (both excluded)
- Any number not between 10 and 100 (both excluded)
What is the correct way of creating an array of int of size 5 named myArray?
- int[] myArray = new int[5];
- int[] myArray = int[5];
- int[5] myArray = new int[];
- int[4] myArray = new int[];
- int myArray = new int[5];
- int[] myArray = new int[4];
- int[] myArray = new int(5);
- int[] myArray = int[4];
Consider the following code:
```
int[] grades = {10, 20, 5, 15};
Console.WriteLine(grades[2]);
```
What will it display?
- 5
- Nothing
- 20
- 15
- grades
- grades[2]
- 10
Consider the following code:
```
char[] grades = {'A', 'B', 'C', 'D', 'F'};
int i = 0;
while(i < grades.Length){
    i++;
    Console.WriteLine(grades[i]);
}
```
Something is wrong with it, can you tell what?
- There will be an “Index was outside the bounds of the array.” error.
- The array is not properly initialized.
- The loop is infinite
- grades.Length is not declared.
What will be displayed by the following code?
```
for (int e = -5; e <= 20; e += 5)
{
    Console.Write(e + " ");
}
```
- -5 0 5 10 15 20
- -5 0 5 10 15
- 0 5 10 15
- -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
- Nothing
- 0 5 10 15 20

What will be displayed by the following code?

int variable = 0;
for (int e = 1; e <= 5; e += 1)
{
    variable += e;
}    
Console.WriteLine(variable);

15
0
Nothing
1 2 3 4 5