My first typescript / Typescript in 5 minutes.

my-first-typescript.ts

/*!
  My first typescript | NDF, 15-Oct-2019.

  https://typescriptlang.org/docs/handbook/typescript-in-5-minutes.html
*/

class Student {
    fullName: string;

    constructor(public firstName: string, public middleInitial: string, public lastName: string) {
        this.fullName = `${ firstName } ${ middleInitial } ${ lastName }`;
        // this.fullName = firstName + " " + middleInitial + " " + lastName;
    }
}

interface Person {
    firstName: string;
    lastName: string;
}

function greeter(person: Person) {
    return `Hello, ${ person.firstName } ${ person.lastName }!`; // "Hello, " + person.firstName + " " + person.lastName;
}

let user = new Student("Jane", "M.", "User");
// let user = { firstName: "Jane", lastName: "User" };

function greeterStr(person: string) {
    return "Hello, " + person;
}

// let user = "Jane User";
// let user = [ 0, 1, 2 ]; // TSError.

console.log(greeter( user ));


/* ------------------------------------------------------------------ */

const _PKG_ = {
  "private": true,
  "name": "@nfreear/my-first-typescript",
  "devDependencies": {
    "ts-node": "^8.4.1",
    "typescript": "^3.6.4"
  },
  "scripts": {
    "build": "tsc index.ts",
    "start": "ts-node index.ts"
  }
}

const _ERROR_ =
`/Users/[_NAME_]/workspace/admins-project/my-first-typescript/node_modules/ts-node/src/index.ts:245
    return new TSError(diagnosticText, diagnosticCodes)
           ^
TSError: ⨯ Unable to compile TypeScript:
index.ts:12:21 - error TS2345: Argument of type 'number[]' is not assignable to parameter of type 'string'.

12 console.log(greeter(user))
                       ~~~~
--

at createTSError (/Users/ndf42/workspace/admins-project/my-first-typescript/node_modules/ts-node/src/index.ts:245:12)
at reportTSError (/Users/ndf42/workspace/admins-project/my-first-typescript/node_modules/ts-node/src/index.ts:249:19)
... `;

// End.