Gavin Wiggins

Strides in Swift

Published on November 12, 2022
Tagged with swift

Use the stride function to step over values between two limits or boundaries. The stride functions can also be used to build arrays with a certain range of numbers.

// Step from start to end and exclude end value

for s in stride(from: 0, to: 10, by: 2) {
    print("s is \(s)")
}
// s is 0
// s is 2
// s is 4
// s is 6
// s is 8

// Step from start to end and include end value

for t in stride(from: 0, through: 10, by: 2) {
    print("t is \(t)")
}
// t is 0
// t is 2
// t is 4
// t is 6
// t is 8
// t is 10

// Create an array from a stride sequence

let w = Array(stride(from: 0, to: 10, by: 2))
print("w is \(w)")
// w is [0, 2, 4, 6, 8]

let y = Array(stride(from: 0, through: 10, by: 2))
print("y is \(y)")
// y is [0, 2, 4, 6, 8, 10]

// Create an array with specified number of steps using values from another array

let a = [3.4, 5, 2, 8.14, 10, 12]
let min = a.min() ?? 0.0
let max = a.max() ?? 1.0

let nSteps = 4.0
let step = (max - min) / nSteps

let z = Array(stride(from: min, through: max, by: step))
print("z is \(z)")
// z is [2.0, 4.5, 7.0, 9.5, 12.0]