TypeScript

Links

• Angular
• RestSv
• MySqlRestServer

Konstanten, Variablen

• 'var'-Variablen sind global, 'let'-Variablen sind lokal (blockgebunden).

const E_DISK: string = 'disk error';
var globalLastMessage: string = 'Error';
for (let i=0; i < 4; i++){}
const myArray = [ 0, 'string', { firstname: 'Joe' } ];
const onlyNumbers: number[] = [ 1, 2, 3];
let arg: any = 5; ... arg = 'string';
let width, height: number;
let rest: number[];
const [width, height] = [1, 2];
const [width, ...rest] = [1, 2, 3, 4]; // rest hat den Wert [2, 3, 4]

Statements

for (let i = 0; i < 3; i++){
  doit(i);
}
let arr = [10, 20, 30, 40];
// for in loops over enumerable property names of an object.
// Loops over keys:
for (var val in arr) {
  doit(val);
}
// for of (new in ES6) does use an object-specific iterator and loops over the values generated by that.
// Loops over values:
for (var val in iterator) {
  doit(val);
}

Typen

String

• " und ' gleichwertig
• `text ${expr}` wird interpretiert

 let x ='Hi';
 x = `2 lines:
Say: ${x}
`;

Array

let a: string[];
a.push('Hi');
a[0] = 'Hello'; a[1] = 'world';
let b = [12.4, 100, -33.4];
let len = b.length;
let series = [1, 2, 3];
var series2 = series.concat(47, 49);
var index = series2.indexOf(47);

// forEach(), map(), reduce(), and filter() 
let doubleIt = series.map(e => e* 2);
let scores : (string | number)[];
scores = ['Programming', 5, 'Software Design', 4]; 

• Assoziatives Array:

var information = new Array();
information["key1"] = 25;

const array1 = { “one”: 1, “two”: 2, “three”: 3 };
const iterator = array1.keys();

for (const key of iterator) {
  console.log(key);
}

Enums

typedef Status = 'active' | 'inactive';

Funktionen/Methoden

# default parameters:
getList(offset: number=0, count: number=20){
  ...
}

Klassen

• Nur ein Konstruktor

class User {
  publicItems: string;
  private privateMember: string = 'secret';
  private privateNumber = 25; // impliziter Typ.
  constructor(items: string){
    this.privateItems = items;
  }
  append(item: string): string { this.publicItems += ';' + item; return this.publicItems; }
  // getter + setter:
  get currentNumber(): number { return this.privateNumber; }
  set number(value: number): void { this.privateNumber = value; }
  add(inc: number) => return privateNumber + number;
  printAll(...args): void {
    print(args[0] + ': ' + args);
  }
}
class SuperUser extends User {
  constructor(items: string){
    super(items);
  }
}

Interfaces

interface Contact {
  firstname: string;
  lastname: string;
}
const contact: Contact = {
  firstname: 'Joe',
  lastname: 'Doo'
}
class Address implements Contact {
  firstname = 'Eve';
  lastname = 'Smith';
}

Operatoren

instanceof

if (element instanceof HTMLElement){
  doIt();
}

spread-Operator

let list1: number[] = [1, 2, 3];
let list2: number[] = [...list, 4, 5, ..list];
myFunc(1, 2, 3);
myFunc(...list1);