Warm-up Exercises
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Explain Boolean type bool and the meaning of logical operations AND (&&), OR (||) and negation (!). Provide a small example.
Solution
The boolean data type holds either of the two values true or false. The AND and OR operators are used to evaluate multiple conditions. The AND returns true if all conditions are true, and the OR operator returns true if at least one of them is true. The negation operator changes a boolean value into its opposite.
Example:
bool b1 = true, b2 = false;
Console.Write(b1 && !b2); // outputs true
Console.Write(b1 || b2); // outputs true- Declare a variable of type int, with value 3.
Solution
int num = 3;Questions
- Write a statement that initializes a variable named myHeightInMeters to your height in meters. What should be the datatype of myHeightInMeters, and why?
Solution
decimal myHeightInMeters = 1.74m; The datatype should be decimal
because a person’s height in meters most likely needs the precision
afforded by the decimal type.
- What is wrong with the following? Will the error(s) appear at compilation time, or at execution time?
int age;
Console.WriteLine("Please enter your age:");
age = Console.ReadLine();
Solution
Console.ReadLine() returns a value of type string, which cannot be
stored in an integer variable. This results in a compile time error?
- What is the difference, if any, between 3 and “3”?
Solution
3 is an integer value, and “3” is a string value.
Problems
- Declare and initialize 3 variables:
- Each variable should have a different data type
- Choose an appropriate name and value for each variable Then display the value of each variable on the screen.
Solution
int number = 5;
string name = "Samuel";
float weight = 120.65f;
Console.WriteLine($"number: {number}");
Console.WriteLine($"name: {name}");
Console.WriteLine($"weight: {weight} kg");