Variables allow us to save data during our program execution. For example, in an RPG video game, your character has attributes such as health, magic, stamina, etc. These are values that need to be tracked throughout the game. Variables allow us to store this data and use it throughout the program.
In C#, creating a variable is known as declaring a variable. When we want a variable to ‘store’ some value, this is known as variable assignment. We use the equal sign = to assign a value to a variable. We can both declare and assign a value in one line, which is known as initialization. We will start by using three data types: string, int, and double.
When declaring a variable, the data type must be specified. Once the data type is declared, the variable can only ever store data of that type. This is known as static typing.
// Declare a string variable.
string name;
// Assign a value to name.
// No need to use the string keyword after the variable has been declared.
name = "Anthony";
// Initialize an integer and a double variable.
int age = 5;
double weight = 500.55;
name = 10; // BAD! name is a string. This will cause an error.
// String variables
string name = "Anthony"; // Replace the name with your name;
string food = "Steak"; // Replace the food with your favorite food;
string item = "peppers";
Console.WriteLine($"Hello, this is {name}!");
Console.WriteLine($"{name} likes the stinkiest of {food}.");
Console.WriteLine($"{name} likes {food} so much, he/she eats it out of the garbage!");
Console.WriteLine();
Console.WriteLine($"Peter Piper picked a peck of pickled {item}");
Console.WriteLine($"A peck of pickled {item} Peter Piper picked");
Console.WriteLine();
// Numbers
int age = 30; // Replace the number with your age
Console.WriteLine($"You will reach age 100 in {100 - age} years!");
Console.WriteLine();
double balance = 35.25;
double withdraw = 0; // Replace the 0 with larger number
double leftover = balance - withdraw;
Console.WriteLine($"You have a balance of ${balance} in your bank account.");
Console.WriteLine($"If you withdraw ${withdraw}, you will have ${leftover}.");
Console.WriteLine();
int health = 100;
double damage = 55.5;
Console.WriteLine($"You've taken {damage} damage. You have {health - damage} health left.");
Hello, my name is Anthony
Anthony likes the stinkiest of Steak.
Anthony likes Steak so much, he/she eats it out of the garbage!
Peter Piper picked a peck of pickled peppers
A peck of pickled peppers Peter Piper picked
You will reach age 100 in 70 years!
You have a balance of $35.25 in your bank account.
If you withdraw $0, you will have $35.25.
You've taken 55.5 damage. You have 44.5 health left.
var for declaring variables. This is known as type inference, and we will check out how
it works shortly.