TypeScript - object types

let a = [ 1, 2, 3 ];

let b : number[] = [ 1, 2, 3 ];

let c : Array<number> = [ 1, 2, 3 ];

let d : (number|string)[] = [ 1, 2, 'text' ];

let e : Array<number|string> = [ 1, 2, 'text' ];

​

console.log(a);

console.log(b);

console.log(c);

console.log(d);

console.log(e);

[ 1, 2, 3 ]

[ 1, 2, 3 ]

[ 1, 2, 3 ]

[ 1, 2, 'text' ]

[ 1, 2, 'text' ]

let a = [ 1, 'text' ];

let b : [number, string] = [ 1, 'text' ];

​

console.log(a);

console.log(b);

[ 1, 'text' ]

[ 1, 'text' ]

interface IOperator {

    make(a : number, b : number) : number;

}

​

class Summator implements IOperator {

    public make(a : number, b : number) : number {

        return a + b;

    }

}

​

let summator = new Summator();

//let summator : IOperator = new Summator();

//let summator : Summator = new Summator();

​

let a = summator.make(1, 2);

let b = summator.make(3, 4);

​

console.log(`1 + 2 = ${a}`);

console.log(`3 + 4 = ${b}`);

1 + 2 = 3

3 + 4 = 7

class Person {

    public constructor(private name : string, private age : number) {

        // nothing here...

    }

​

    public print() : void {

        console.log(`name: ${this.name}, age: ${this.age}`);

    }

}

​

let a = new Person('John', 43);

let b = new Person('Kate', 21);

​

a.print();

b.print();

name: John, age: 43

name: Kate, age: 21

enum Role {

    Admin,

    Moderator,

    User

}

​

enum Size {

    Samll = 10,

    Mmedium = 20,

    Big = 30

}

​

enum Planet {

    Earth = 'Earth',

    Mars = 'Mars',

    Jupiter = 'Jupiter'

}

​

let a = Role.Moderator;

let b : Role = Role.User;

​

let c : number = Size.Mmedium;

let d : Size = Size.Big;

​

let e : string = Planet.Mars;

let f : Planet = Planet.Jupiter;

​

console.log(Role.Admin);

console.log(a);

console.log(b);

​

console.log(Size.Samll);

console.log(c);

console.log(d);

​

console.log(Planet.Earth);

console.log(e);

console.log(f);

0

1

2

10

20

30

Earth

Mars

Jupiter

let f1 = function() { console.log('Hello world!'); };

let f2 = function() : void { console.log('Hello world!'); };

let f3 = () => console.log('Hello world!');

let f4 = () : void => console.log('Hello world!');

let f5 = new Function('console.log(\'Hello world!\')');

​

let f6 : Function = function() { console.log('Hello world!'); };

let f7 : Function = function() : void { console.log('Hello world!'); };

let f8 : Function = () => console.log('Hello world!');

let f9 : Function = () : void => console.log('Hello world!');

let f10 : Function = new Function('console.log(\'Hello world!\')');

​

f1(); f2(); f3(); f4(); f5();

f6(); f7(); f8(); f9(); f10();

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!

Hello world!