Interactive online tutorials for JavaScript

The number of free (or low cost) online tutorials for developers to learn programming today is outstanding. Never before have learning resources been so easily accessible.

My favorite type of tutorial are the interactive style where you get to work on a solution to a problem online and the site checks your result and gives you feedback. Compared to a static tutorial where you just read materials or watch a video, this additional interactive step really helps to apply your understanding at a practical level.

(NOTE: list in progress – last updated 11/03/20)

These are some of my favorite interactive learning resources:

Learning Golang (part 2)

It’s been several months since I started to look at Golang, but I’ve been picking it back up again. The design decisions in the language are starting to make me like this language more and more. It’s clear there were decisions made to address many pet peevs with other languages. Here’s a few I’ve noticed:

  • standard formatting and the ‘go fmt’ tool. In many other languages there’s endless debates about where your { and } should go, and honestly it really doesn’t matter. Go addresses this by requiring a single style where the opening { is syntactically required at the end of the line (and not allowed on the following line) in order for your code to compile. End of argument. Done
  • a single for loop for iteration. Other languages support for and while in a few different variations (while condition at the beginning of a block or at the end), but Go has a ‘for’ statement and that’s it. Keep it simple.
  • much time has been wasted in Java arguing about whether exceptions should be checked or unchecked. Go’s approach, no exceptions, no exception handling. You have an ‘error’ type which you can chose to return as the last return value from a function if needed

Here’s my notes following on from my earlier Part 1.

Imports

Imports are each on a separate line, with the package in quotes:

import "fmt"
import "unicode/utf8"

Variables

Variable types are defined after the variable name, both in variable declaration and function parameters:

func ExampleFunc(x int, y int) int {
var example int
var example2 string
...
return 1
}

This function takes 2 params, both ints, and returns an int.

Unlike other languages where you can pass many params but only return a single result, Go functions allows you to return multiple results, e.g.

func ExampleFunc(x int, y int) (int, int) {
var example int
var example2 string
...
return a, b
}

To call this function and receive the multiple results:

x, y := ExampleFunc(1, 2)

If you’re only interested in one of the return values you can use the blank identified to ignore one of the returned values:

_, y := ExampleFunc(1, 2)

Functions with a capital first letter are exported so they can be imported elsewhere, functions with a lowercase first letter are not.