# stride(from:through:by:)

Returns a sequence from a starting value toward, and possibly including, an end value, stepping by the specified amount.

`func stride<T>(from start: T, through end: T, by stride: T.Stride) -> StrideThrough<T> where T : Strideable`

## Parameters

- start
The starting value to use for the sequence. If the sequence contains any values, the first one is

`start`

.- end
An end value to limit the sequence.

`end`

is an element of the resulting sequence if and only if it can be produced from`start`

using steps of`stride`

.- stride
The amount to step by with each iteration. A positive

`stride`

iterates upward; a negative`stride`

iterates downward.

## Returns

A sequence from `start`

toward, and possibly including, `end`

. Each value in the sequence is separated by `stride`

.

## Overview

You can use this function to stride over values of any type that conforms to the `Strideable`

protocol, such as integers or floating-point types. Starting with `start`

, each successive value of the sequence adds `stride`

until the next value would be beyond `end`

.

```
for radians in stride(from: 0.0, through: .pi * 2, by: .pi / 2) {
let degrees = Int(radians * 180 / .pi)
print("Degrees: \(degrees), radians: \(radians)")
}
// Degrees: 0, radians: 0.0
// Degrees: 90, radians: 1.5707963267949
// Degrees: 180, radians: 3.14159265358979
// Degrees: 270, radians: 4.71238898038469
// Degrees: 360, radians: 6.28318530717959
```

You can use `stride(from:through:by:)`

to create a sequence that strides upward or downward. Pass a negative value as `stride`

to create a sequence from a higher start to a lower end:

```
for countdown in stride(from: 3, through: 1, by: -1) {
print("\(countdown)...")
}
// 3...
// 2...
// 1...
```

The value you pass as `end`

is not guaranteed to be included in the sequence. If stepping from `start`

by `stride`

does not produce `end`

, the last value in the sequence will be one step before going beyond `end`

.

```
for multipleOfThree in stride(from: 3, through: 10, by: 3) {
print(multipleOfThree)
}
// 3
// 6
// 9
```

If you pass a value as `stride`

that moves away from `end`

, the sequence contains no values.

```
for x in stride(from: 0, through: 10, by: -1) {
print(x)
}
// Nothing is printed.
```