From 87915b885cbc1c5bd8fb0b15905f1d8c95012ceb Mon Sep 17 00:00:00 2001
From: Jungpyo Hong <ghdwjdvy96@gmail.com>
Date: Wed, 23 Jun 2021 05:37:35 -0500
Subject: [PATCH] update dependency injection

---
 README.md | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/README.md b/README.md
index a32403e..e25fa2f 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,7 @@ Feel free to fork this repository and pull requests!!
 - [Design Pattern](#Design-Pattern)
     - [Adaptor](#Adaptor)
     - [Delegation](#Delegation)
+    - [Dependency Injection](#Dependency-Injection)
     - [Factory](#Factory)
     - [Observer](#Observer)
        - [KVO](#KVO)
@@ -155,6 +156,10 @@ Check [this](https://refactoring.guru/design-patterns/swift) website for design
 ```swift
 weak var delegate: SomeProtocol?
 ```
+## Dependency Injection
+
+[Nuts and Bolts of Dependency Injection in Swift](https://cocoacasts.com/nuts-and-bolts-of-dependency-injection-in-swift)
+
 
 ## Factory
 
@@ -183,6 +188,8 @@ For more info, go [Apple Developer Site](https://developer.apple.com/documentati
 
 ## Singleton
 
+singleton pattern is to ensure only one instance of a class is alive at any one time.
+
 ```swift
 class SingletonPattern {
     static let manager = SingletonPattern()