Intro to C# and .NET by Spencer Schneidenbach – From Beginner to Professional

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Operators

Operators are used to perform operations on variables and values. They can be used to mutate values, perform arithmetic operations, make comparisons, and more.

Arithmetic

Overview

This section covers basic arithmetic operators used in programming for performing mathematical operations.

Addition (+)

  • Adds two operands.
  • Example: a + b

Subtraction (-)

  • Subtracts the second operand from the first.
  • Example: a - b

Multiplication (*)

  • Multiplies two operands.
  • Example: a * b

Division (/)

  • Divides the numerator by the denominator.
  • Example: a / b

Modulus (%)

  • Returns the remainder of a division operation.
  • Example: a % b

Increment (++)

  • Increases the value of an operand by one.
  • Example: a++ or ++a

The difference between a++ and ++a is that a++ returns the value of a before incrementing, while ++a returns the value of a after incrementing.

Example:

int a = 5;
int b = a++; // b is 5, a is 6
int c = ++a; // c is 7, a is 7

Decrement (--)

  • Decreases the value of an operand by one.
  • Example: a-- or --a

Examples

int a = 5;
int b = 3;
int sum = a + b; // 8
int difference = a - b; // 2
int product = a * b; // 15
int quotient = a / b; // 1
int remainder = a % b; // 2

Relational/Comparison

This section explores relational and comparison operators used to compare values and determine their relationships.

Equal to (==)

  • Checks if two operands are equal.
  • Example: a == b

Not equal to (!=)

  • Checks if two operands are not equal.
  • Example: a != b

Greater than (>)

  • Checks if the left operand is greater than the right.
  • Example: a > b

Less than (<)

  • Checks if the left operand is less than the right.
  • Example: a < b

Greater than or equal to (>=)

  • Checks if the left operand is greater than or equal to the right.
  • Example: a >= b

Less than or equal to (<=)

  • Checks if the left operand is less than or equal to the right.
  • Example: a <= b

Examples

int a = 5;
int b = 3;
bool isEqual = (a == b); // false
bool isNotEqual = (a != b); // true
bool isGreater = (a > b); // true
bool isLess = (a < b); // false
bool isGreaterOrEqual = (a >= b); // true
bool isLessOrEqual = (a <= b); // false

Logical Operators

This section covers logical operators used to perform logical operations on boolean values.

Conditional logical AND (&&)

  • Returns true if both operands are true. Does not evaluate the right operand if the left operand is false.
  • Example: a && b

Logical AND (&)

  • Returns true if both operands are true. Always evaluates both operands (unless an exception is thrown).
  • Example: a & b

Conditional logical OR (||)

  • Returns true if at least one of the operands is true. Does not evaluate the right operand if the left operand is true.
  • Example: a || b

Logical OR (|)

  • Returns true if at least one of the operands is true. Always evaluates both operands (unless an exception is thrown).
  • Example: a | b

Logical NOT (!)

  • Inverts the boolean value of the operand.
  • Example: !a

Examples

bool a = true;
bool b = false;
bool andResult = (a && b); // false
bool orResult = (a || b); // true
bool notResult = !a; // false

Assignment Operators

This section explores assignment operators used to assign and modify values of variables.

1. Assignment (=)

  • Assigns a value to a variable.
  • Example: a = b

2. Addition Assignment (+=)

  • Adds a value to a variable and assigns the result.
  • Example: a += b (equivalent to a = a + b)

3. Subtraction Assignment (-=)

  • Subtracts a value from a variable and assigns the result.
  • Example: a -= b (equivalent to a = a - b)

4. Multiplication Assignment (*=)

  • Multiplies a variable by a value and assigns the result.
  • Example: a *= b (equivalent to a = a * b)

5. Division Assignment (/=)

  • Divides a variable by a value and assigns the result.
  • Example: a /= b (equivalent to a = a / b)

6. Modulus Assignment (%=)

  • Calculates the modulus of a variable with a value and assigns the result.
  • Example: a %= b (equivalent to a = a % b)

Examples

int a = 5;
int b = 3;
a += b; // a is now 8
a -= b; // a is now 5
a *= b; // a is now 15
a /= b; // a is now 5
a %= b; // a is now 2