TypeScript training notes

[justinbmeyer]

• Guide should be tested in windows. npm run solutions

• on the homepage, this link does not work

• The following isn't indented correctly:

   function bonusMaker(multiplier: number, ...names: string[]) {
    let total = 0;
    for(var i = 0; i < names.length; i++) {
      total = total + names[i].length;
     
     return multiplier*total;
   }
  

• We should include a verifying solution section, so people know what commands to run.

• Overviews should hint at the exercise.

[justinbmeyer]

Why TypeScript

• We probably need a larger explanation of the test suite and how it works. Merge solutions. https://github.com/bitovi/academy/tree/typescript-updates

[justinbmeyer]

Types

• The following example needs to be improved. It felt unnecessary:

let someValue: any = "this is a string";

let strLength: number = (<string>someValue).length;

let otherValue: any = "this is a string";

let otherLength: number = (otherValue as string).length;

I used the example from Angular/RxJS.

something like:

import notTypeScriptFunc from "lib";


notTypeScriptFunc(1,2,3) as number

[justinbmeyer]

Functions

• The bonus maker example is a bit odd. I'd like to come up with something a bit nicer. Desired:
  • includes a return value

function legacyMultiply(a: any, b:any): any {
	return a * b;
}


function bonusMaker(multiplier: number, ...names: string[]): number {
  let total = 0;
  for(var i = 0; i < names.length; i++) {
    total = total + names[i].length;
  }
  return legacyMultiply( multiplier, total);
}

• The solution includes <script> tags. We need to update so we can @sourceref .ts files. (Justin)

[justinbmeyer]

Classes

• It would be nice to have an intermediate "JS-only" class between the constructor-function example and the typescript class example.

• I got a lot of questions about super. It might be worth having a link to its mechanics in JS.

• move(distanceInFeet: number = 0) { shows default values. Questions if this was typescript or not.

• In Statics What does the second statics example class RaptorCage extends DinoCage { show? What should someone learn from it? P2

• Readonly allows unlimited "internal" sets right? It shows a property being set. It says "not changed" but not changed externally? P2

• Might want to change let fierce = dino.roar; fierce(); to use setTimeout(dino.roar). Also maybe not use name b/c window.name is ""

• We should split the tests so things can be verified on their own.

 IS-a VS HAS-a
// instead of 
d = new Dino()

d.eat()


// do this 
eat({})

[justinbmeyer]

Interfaces

• Interfaces in Functions - long example, hard to follow

• Describing Objects - seems to explain something we've seen.

• Describing Functions - seems to explain something we've seen.

• Add describing function interfaces.

• Exercise 1 doesn't show how to test it. I think the explanation could be a bit more clear. P0