In a programming language, operators are special symbols such as `+`

, `-`

, `^`

, etc., that perform some action on operands. The **NReco.LambdaParser** 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.

Below is a list of the different types of operators

Type | Operators |
---|---|

Arithmetic | `-` , `+` , `*` , `/` , `%` |

Logical | `&&` , `\|\|` , `!` |

Comparison | `==` ,`!=` , `>` , `<` , `>=` , `<=` |

String Concatenation | `+` |

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 script = @"
int a = 10;
int b = 20;
Console.WriteLine(""a + b = {0} "", a + b);
Console.WriteLine(""a - b = {0}"", a - b);
Console.WriteLine(""a * b = {0}"", a * b);
Console.WriteLine(""a + b = {0}"", a + b);
Console.WriteLine(""a + b = {0}"", a + b);
";
ExpressionEvaluator evaluator = new ExpressionEvaluator();
Console.WriteLine(evaluator.ScriptEvaluate(script));
}
```

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

```
a + b = 30
a - b = -10
a * b = 200
a + b = 30
a + b = 30
```

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.

A | B | A && B | A || B |
---|---|---|---|

true | true | true | true |

true | false | false | true |

false | true | false | true |

false | false | false | false |

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

```
public static void Example2()
{
var varContext = new Dictionary<string, object>()
{
{ "a", true },
{ "b", false },
};
List<string> expressions = new List<string>()
{
"a || b",
"a && b",
"!b",
"true || b",
};
var lambdaParser = new NReco.Linq.LambdaParser();
foreach (var expression in expressions)
{
var result = lambdaParser.Eval(expression, varContext);
Console.WriteLine("{0} = {1}", expression, result);
}
}
```

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 Example3()
{
var varContext = new Dictionary<string, object>()
{
{ "a", 10 },
{ "b", 6 },
};
List<string> expressions = new List<string>()
{
"a > b",
"a < b",
"a == b",
"a != b",
"a >= b",
"a <= b",
};
var lambdaParser = new NReco.Linq.LambdaParser();
foreach (var expression in expressions)
{
var result = lambdaParser.Eval(expression, varContext);
Console.WriteLine("{0} = {1}", expression, result);
}
}
```