swift-for-python-programmers

Miscellaneous

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Table of contents

1. Type Conversion
2. Decomposing
3. Optional Binding
4. Functional Parameters
5. Wildcard Patterns

1. Type Conversion

We can convert a 8 bit unsigned integer to an 16 bit one much like you do in Python

let twoThousand: UInt16 = 2_000
let one: UInt8 = 1
let twoThousandAndOne = twoThousand + UInt16(one)

2. Decomposing

Unpacking in Python is called Decomposing here

let http200 = (200, "OK")

let (status_code, message) = http200

Similary you can also ignore values using _, this is called a Wildcard Pattern

3. Optional Binding

Somewhat like the whalrus operator once can have an assigment operation inside a conditional

let numStr = "123"

if let numInt = Int(numStr) {
    print("The string \"\(numStr)\" has an integer value of \(numInt)")
} else {
    print("The string \"\(numStr)\" couldn't be converted to an integer")
}

4. Function parameters

Passing named parameters to a Swift function follows the type annotatin syntax

func greet(person: String) -> String {
    let greeting = "Hello, " + person
    return greeting
}

Is called like

greet(person: "As3tic")

5. Wildcard patterns

A Wildcard pattern can match any value and then ignore it. Like in Python you use one when the value in question doesn’t matter.

for _ in 1...3 {
    // Do something three times.
}