# PartialRangeThrough

A partial interval up to, and including, an upper bound.

`@frozen struct PartialRangeThrough<Bound> where Bound : Comparable`

## Overview

You create `PartialRangeThrough`

instances by using the prefix closed range operator (prefix `...`

).

`let throughFive = ...5.0`

You can use a `PartialRangeThrough`

instance to quickly check if a value is contained in a particular range of values. For example:

```
throughFive.contains(4.0) // true
throughFive.contains(5.0) // true
throughFive.contains(6.0) // false
```

You can use a `PartialRangeThrough`

instance of a collection’s indices to represent the range from the start of the collection up to, and including, the partial range’s upper bound.

```
let numbers = [10, 20, 30, 40, 50, 60, 70]
print(numbers[...3])
// Prints "[10, 20, 30, 40]"
```