Ncalc Operators

In a programming language, operators are special symbols such as +, -, ^, etc., that perform some action on operands. The CoreCLR-NCalc library manages a large set of C# operators, and it also respects the C# precedence rules of operators.

• Operators allow the processing of primitive data types and objects.
• They take as an input one or more operands and return some value as a result.

For example, operators are the signs for adding, subtracting, multiplication, and division like +, -, *, /, and the operations they perform on the integers and the real numbers.

Types

Below is a list of the different types of operators which are most common.

Arithmetical

In C#, the arithmetical operators are +, -, *, etc., and they perform mathematical operations such as addition, subtraction, and multiplication respectively on numerical values and the result is also a numerical value.

Here are some examples of arithmetic operators and their effects.

public static void Example1()
{
    string expression = string.Format("3 + 6");
    Expression evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("3 - 6");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("3 * 6");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("3 / 6");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("3 % 6");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());
}

Let's run the above code, and you will see the following output.

3 + 6 = 9
3 - 6 = -3
3 * 6 = 18
3 / 6 = 0.5
3 % 6 = 3

Logical

Logical operators or you can say Boolean operators take Boolean values and return a Boolean result (true or false).

The following table contains the logical operators in C# and the operations that they perform.

Let's consider the following simple examples of logical operators.

public static void Example2()
{
    string expression = string.Format("true || false");
    Expression evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("true or false");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("true && false");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("true and false");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("true or false and true");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("!false");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());
}

The and operator has more priority than the or, thus in the example above, false and true are evaluated first.

Bitwise

A bitwise operator is an operator that acts on the binary representation of numeric types.

• In computers, all the data and particularly numerical data are represented as a series of ones and zeros.
• For example, number 55 in the binary numeral system is represented as 00110111.

public static void Example3()
{
    string expression = string.Format("2 >> 3");
    Expression evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("2 << 3");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("2 & 3");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("2 | 3");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("2 ^ 3");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("~false");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());
}

Comparison

Comparison operators are used to comparing two or more operands. C# supports the following comparison operators.

• greater than (>)
• less than (<)
• greater than or equal to (>=)
• less than or equal to (<=)
• equality (==)
• difference (!=)

The following example shows the usage of comparison operators.

public static void Example4()
{
    string expression = string.Format("2 > 3");
    Expression evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("2 < 3");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("2 >= 3");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("2 <= 3");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("2 != 3");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());

    expression = string.Format("2 == 3");
    evaluator = new Expression(expression);
    Console.WriteLine("{0} = {1}", expression, evaluator.Evaluate());
}