Workshop Typescript exercise on data types and functions.

The main purpose of this exercise is to get familiar with Typescsript's data types and function declarations.

For this exercise you need to have NodeJs

NodeJS

and also Typescript installed

$ npm i -g typescript

Given a language that uses only 4 letters

{ A, T, G, C}

and a grammar of the following 2 rules

A can only pair with T, and vice versa
G can only pair with C, and vice versa

so it is:

A -> T
T -> A
G -> C
C -> G

Create a function that takes any sequence of those 4 letters and replies with a sequence of the complementary letters i.e the letters they pair with.

So if sequence is

ATGCATCAGACT

Then the solution should be

TACGTAGTCTGA

Try and be more strict when declaring a variable

const myVar = 'anything';   // Bad!
const myVar: string = 'anything';  // Good!

and also when declaring a function

const add = (x, y) => x + y; // Bad!
const add = (x: number, y: number): number => x + y; // Good!

If you need to convert an enum to string

enum Base { A, T, G, C}
const name: string = Base[Base.A];

If you like, we have provided a file containing a sequence

collagen.ts

You may import it like this

import {collagen} from './collagen';

To compile and run your code

$ tsc your_file.ts && node your_file.js