# Using Pattern Matching

Pattern Matching is one of the fundamental concepts of functional programming.

This concept can be used to replace a lot of code flow structures, such as:

* If-else statements 
* Switch-cases
* Loops (for, foreach, while e do)
* Types comparison

A pattern matching in the F# language to replace an if statement has a syntax similar to:

```fsharp
match boolExpression with
| true  -> //pattern when true 
| false -> //pattern when false
```

You can also using patterns to compare an `int` value:

```fsharp
let value = 10
match value with
| 1 | 2 | 3         -> //When the value is 1, 2 or 3
| n when n % 2 = 0  -> //When the value is an even number
| 5                 -> //When the value is equals to 5
| _                 -> //Other cases
```

There are a lot of benefits to using pattern matching, so, from C# 7.0 version it is possible to use this feature natively in the language, according to the documentation of the [Microsoft](https://docs.microsoft.com/pt-br/dotnet/csharp/pattern-matching).

As an implementation in **Tango** library, some types have a method called `Match`.

These methods receive lambda expressions for each pattern as a parameter, according to each type.

Besides that, there are also an implementation of a method called `Match2`, similar to the previous one, but in this case, the patterns are applied to two different values simultaneously.


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