10 Tips to become a better Swift Developer

Type less, read less, produce more | Update on May 14th, 2017

Not my desk

So, you’ve been around with Swift for a couple of months. Now, you want to become a better Swift Developer? DRY, KISS, and not WET? I’ve got golden nuggets here and there for you.

Excuse me for the formatting, I tried to have as fewer lines as possible for conciseness. Feel free to copy and paste into Playground to check if everything works. 👊 If not, please comment below. I will fix them asap.

I have also embedded YouTube lessons under each part for an explanation.

I talked too much. Let’s get started.

1. Extension

Ex) Square a number

// Okay Version
func square(x: Int) -> Int { return x * x }
var squaredOFFive = square(x: 5)
square(x:squaredOFFive) // 625

The useless variable was created to double square 5— we need not enjoy typing.

// Better Version
extension Int { 
 var squared: Int { return self * self }
}
5.squared // 25
5.squared.squared // 625

Extension Lesson

2. Generics

Ex) Print all elements in an array

// Bad Code
var stringArray = ["Bob", "Bobby", "SangJoon"]
var intArray = [1, 3, 4, 5, 6]
var doubleArray = [1.0, 2.0, 3.0]
func printStringArray(a: [String]) { for s in a { print(s) } }
func printIntArray(a: [Int]) { for i in a { print(i) } }
func printDoubleArray(a: [Double]) {for d in a { print(d) } }

Too many useless functions. Let’s create just one.

// Awesome Code
func printElementFromArray<T>(a: [T]) {
 for element in a { print(element) } }

Generic Lesson

3. For Loop vs While Loop

Ex) Print “Count” 5 times

// Okay Code
var i = 0
while 5 > i {
print("Count")
i += 1 }

You made the variable “i” to make sure your computer doesn’t break by printing limited numbers

Listen, more variables → more memorization → more headache → more bugs → more life problems.

Remember the Butterfly effect.

// Better Code
for _ in 1...5 { print("Count") }

“Gorgeous” — Bob

For Loop Lesson

4. Optional Unwrapping

Ex) Gaurd let vs if let

Let’s make a program for welcoming a new user.

var myUsername: Double?
var myPassword: Double?
// Hideous Code
func userLogIn() {
 if let username = myUsername {
  if let password = myPassword {
   print("Welcome, \(username)"!)
  }
 }
}

Do you see the pyramid of doom? Those are nasty nested code. Never. Destroy the bad, bring the good.

// Pretty Code
func userLogIn() {
 guard let username = myUsername, let password = myPassword 
  else { return } 
 print("Welcome, \(username)!") }

The difference is trendemous. If username or password has a nil value, the pretty code will early-exit the function by calling “return”. If not, it will print the welcoming message. No Pyramid. 🤘

The content has been migrated from Medium to personal platform. You can read the rest of the content about the other 6 Swift tips here