C# Operators: Arithmetic & Relational

• Operators are symbols for mathematical or logical processing in programming.
• Operators specify the operations performed on operands.
• C# operators include: arithmetic, relational, logical, and assignment operators.

Arithmetic Operators

• Arithmetic operators perform mathematical operations on numerical values.

Basic Arithmetic Operators

• Addition (+): Adds two operands.
  • Example: a + b (if a = 11, b = 5) returns 16.
• Subtraction (-): Subtracts second operand from the first.
  • Example: a - b returns 6.
• Multiplication (*): Multiplies two operands.
  • Example: a * b returns 55.
• Division (/): Divides the first operand by the second.
  • Example: a / b returns 2.
• Modulus (%): Returns the remainder of dividing the first operand by the second.
  • Example: a % b returns 1.

Relational Operators

• Relational operators determine relationships between numeric operands.
• They return Boolean values: true or false.
• Greater Than (>): Checks if the first operand is greater than the second.
  • Example: a > b (if a = 11, b = 5) returns true.
• Less Than (<): Checks if the first operand is less than the second.
  • Example: a < b returns false.
• Greater Than or Equal To (>=): Checks if the first operand is greater than or equal to the second.
  • Example: a >= b returns true.
• Less Than or Equal To (<=): Checks if the first operand is less than or equal to the second.
  • Example: a <= b returns false.
• Equal To (==): Checks if two operands are equal.
  • Example: a == b returns false.
• Not Equal To (!=): Checks if two operands are not equal.
  • Example: a != b returns true.

Logical Operators

• Logical operators perform logical operations using logical expressions.
• These operators return a Boolean value.

Logical Operators

• AND (&&): Returns true if both operands are true, else false.
  • Example: A && B (if A = true, B = false) returns false.
• OR (||): Returns true if at least one operand is true, else false.
  • Example: A || B returns true.
• XOR (^): Returns true if only one operand is true, else false.
  • Example: A ^ B returns true.
• NOT (!): Reverses a Boolean variable's value.
  • Example: !A returns false.

Assignment Operators

• Assignment operators assign a value or expression result to a variable.

Assignment Operators

• Assign (=): Assigns a value or expression to the left variable.
  • Example: b = a (if a = 2, b = 5) assigns the value of a to b, so b now equals 2.
• Add and Assign (+=): Adds the left operand to the first operand and assigns the result to the first operand.
  • Example: b += a means b = b + a, so b now equals 7.
• Subtract and Assign (-=): Subtracts the second operand from the first and assigns the result to the first operand.
  • Example: b -= a; If b is 5 and a is 2, b becomes 3.
• Multiply and Assign (*=): Multiplies both operands and assigns the result to the first operand.
  • Example: b *= a; If b is 5 and a is 2, b becomes 10.
• Divide and Assign (/=): Divides the first operand by the second and assigns the result to the first operand.
  • Example: b /= a; If b is 5 and a is 2, b becomes 2.
• Modulus and Assign (%=): Assigns the remainder of the first operand divided by the second to the first operand.
  • Example: b %= a; If b is 5 and a is 2, b becomes 1.
• Increment (++) Adds 1 to the first operand and assigns the result to the first operand.
  • Example: b++ means b = b + 1, so b now equals 6.
• Decrement (--) Subtracts 1 from the first operand and assigns the result to the first operand.
  • Example: b-- means b = b - 1, so b now equals 4.

Expressions

• An expression is a combination of operands and operators evaluating to a single value.
• Integer Expressions: Evaluates to an integer value when all operands are integers.
  • Example: int x = 10 + 5 * 2; evaluates to 20.
• Floating-Point Expressions: Evaluates to a floating-point value if the operands are floating-point values.
  • Example: double y = 10 + 5 * 2.0; evaluates to 20.0.

Precedence and Associativity

• Operator precedence dictates the order of operator evaluation in an expression.
• Higher precedence operators are executed before lower precedence ones.
• Associativity determines evaluation order when operators share the same precedence.
• When operators of the same precedence are used in a single expression, they are evaluated from left to right.
• Multiplication has higher precedence than addition; assignment has the lowest.
  • Example: int a = 2 + 3 * 4; evaluates multiplication first (3 * 4), then adds 2.

Math Class

• The System.Math class offers methods for various calculations.
• Pow() raises a number to a specified power.
  • Example: Math.Pow(2, 3) returns 8.
• Exp() raises the constant e to the given power.
• Log() returns the natural and 10-based logarithm, respectively.
• Sqrt() returns the square root of the given number.
• Sign() returns the sign of the specified number.
• Abs() returns the absolute value of a given number.
• Ceiling() returns the smallest integral value larger than or equal to a fractional number.
• Floor() returns the largest integral value smaller than or equal to the given fractional number.
• Round() returns the number after rounding it to the nearest integral value.
• Truncate() returns the number after removing its fractional part.
• Sin() returns the sine of the specified angle.
• Cos() returns the cosine of the specified angle.
• Tan() returns the tangent of the specified angle.
• The methods of Math class are static, and are used with the class name without instantiating an object.