Closures Courses

Functions and Closures in Swift
Udemy

Learn Swift: Closures
Codecademy

Securing the Spark Fire Hose - 2016
LASCON via YouTube

How to Avoid Safety Hazards When Using Closures in Scala
Strange Loop Conference via YouTube

Building Optimising Compiler for Dart
Strange Loop Conference via YouTube

JavaScript Interview Prep: Functions, Closures, Currying
freeCodeCamp

C# Delegates Explained - Functions as Values, Func, Action, and Closures
Raw Coding via YouTube

Essentials Of Topology
IIT (ISM) Dhanbad via Swayam

JavaScript - The Structural Problem
International PHP Conference via YouTube

PHP 5.4 - An Update
International PHP Conference via YouTube