Describes the format and size of (amount of memory occupied by) a data item and defines what types of operations can be performed with the item.

Simple Types: int, double, decimal, char, string, bool

Other Types: String, Object

The statement that names a variable and reserves storage for it. You can have multiple variables on one line

Ex.) int myAge = 24, yourAge = 35;

The process of joining strings together

Ex.) WriteLine("The money is $" + someMoney);

Holds a position for a variable value within a string. It consists of a pair of curly braces containing a number that indicates the desired variable’s position in a list that follows the string. The first position is always position 0.

Ex.) WriteLine("The money is ${0} exactly", someMoney);

The above statement replaces "0" with whatever value is held in the variable someMoney.

A way to insert variables or expressions directly into a string using {}. It starts with a $ before the quotes, making string building easier and more readable.

Ex.)  int someMoney = 45;

string mySentence = $"The money is ${someMoney} exactly.";

WriteLine(mySentence);

Output: The money is $45 exactly.

Stores whole numbers or characters, includes: int, short, long, byte, char, etc.

Contains numbers that can have decimal places

Ex.)

float - Holds up to 7 significant digits of accuracy

double - holds 15-16 digits of accuracy

decimal - holds 28-29 digits of accuracy but smaller range (used in financial applications)

Addition, subtraction, multiplication, division, and remainder. Executes similarly to PEMDAS except you have the remainder operator as well. 

Instead of:

counter = counter +1 

You can shortcut with:

counter+=1;

Alternatives: -=, *=, /=, and %=

int x = 5;

int y = ++x; 

//In this case, x is incremented to 6 before its value is assigned to y.

Console.WriteLine(x);  // Output: 6

Console.WriteLine(y);  // Output: 6

int x = 5;

int y = x++; 

// Here, x++ means y gets the value 5 (the original value of x), and then x is incremented to 6.

Console.WriteLine(x);  // Output: 6

Console.WriteLine(y);  // Output: 5

Can hold only one of two values—true or false. Declared with data type bool. 

Compares two items, an expression containing one of these returns a Boolean value. 

Ex.)

Less Than:                             <

Greater Than:                        >

Equal To:                               ==   

Less Than Or Equal To:        <=

Greater Than Or Equal To:   >=

Not Equal To:                       !=

A method in C# that is used to read input from the console as a string. It waits for the user to type something and press the Enter key, and then it returns whatever was typed as a string.

Ex.)

string name = Console.ReadLine(); 

// Reads user input and stores it in 'name' as a string

Console.WriteLine($"Hello, {name}!");

Convert a string to a number in a different format.

[image]

An Alternative to using the convert class method to convert a string to a number. Turn a string into its numeric equivalent.

Ex.) 

itemPrice = double.Parse(itemPriceAsString);

score = Int32.Parse(ReadLine( ));

Used to represent a single character. Can hold any single letter, number, symbol, or whitespace character. Enclosed in single quotes unlike strings.

Ex.)

____ letter = 'A';

Always begins with a backslash, they are ways to store characters, even nonprinting characters like "tab" in a char variable. Ex.)

\t  - tab

\n - newline

\"anyword"\ - adds quotations around a word

Holds a series of characters, values are expressed within double quotation marks. 

_____ firstName = "Bob";

Equals( ): takes the format name1.Equals(name2); its value is true or false.

CompareTo( ): takes the format name1.CompareTo(name2); and its value is integer—0 when the compared strings are equal, a negative number if the first string is less, and a positive number if the second string (the one in parentheses) is less.

Length: a property not a method, therefore does not need parentheses. It gives you the length of a string. e.g. name.length

StartsWith( ): determines whether a string starts with certain characters and returns true or false. e.g. name.StartsWith("Wi")

Substring( ): Extracts a portion of a string from a starting point for a specific length

[image]