How can I declare several variables within an array directly in TypeScript

Question

I need to declare several variables of the same type (interface) at the time that I declare an array.

I am using it in an Angular 8 project, obviously using typescript.

I have this now:


export class GridComponent {

  pizza0: Pizza;
  pizza1: Pizza;
  pizza2: Pizza;
  pizza3: Pizza;
  pizza4: Pizza;
  pizza5: Pizza;

  constructor() {}

}

interface Pizza {
 name: string;
 ingredients: number;
 price: string;
}

And I want something like:


PizzaList: Array<Pizza> = new Array<Pizza>(pizza0, pizza1, pizza2, pizza3, pizza4, pizza5);


interface Pizza {
 name: string;
 ingredients: number;
 price: string;
}

And that each of the variables that I define within the array are declared initially

What do you mean declared? Initialized as a pizza object? In that case, use a class instead of and interface. — Robby Cornelissen
– Robby Cornelissen, Commented Jun 17, 2019 at 14:22
It is an interface, and I am doing this within an Angular component — Jgascona
– Jgascona, Commented Jun 17, 2019 at 15:42

Rengers · Accepted Answer · 2019-06-18 12:26:25Z

1

I assume you want pizzaList to be an array of Pizza objects. You can create that as follows:

const pizzaList: Array<Pizza> = [
    { name: 'Margherita', ingredients: 1337, price: 9.99 },
    { name: 'Quattro stagioni', ingredients: 1337, price: 9.99 }
];

If you just want to declare it as "An array of pizzas, with length 6", that is not possible. You cannot declare it as a fixed length array of Pizza objects, you can only declare it as an array of pizza objects without specifying the length.

edited Jun 18, 2019 at 12:26

answered Jun 17, 2019 at 16:17

Rengers

15.2k1 gold badge40 silver badges56 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Jgascona Over a year ago

Yes but, I don't want to initialize them, just declare. So I don't want to put all the properties of each object. I just want to say like "I have an array of 6 pizzas with the type pizza": PizzaList: Array<Pizza> = new Array<Pizza>(pizza0, pizza1, pizza2, pizza3, pizza4, pizza5);

Rengers Over a year ago

That is not possible. You cannot define an array with a statically typed length. You can only say: PizzaList: Array<Pizza> to define it as an array of Pizza objects. I have updated my answer.

Harun Yilmaz · Accepted Answer · 2019-06-17 14:25:04Z

0

You can do it without initializing the array with new Array<T>.

If your values are predefined then you can do it like:

PizzaList: Array<Pizza> = [pizza0, pizza1, pizza2, pizza3, pizza4, pizza5];

Or you can create them like:

PizzaList: Array<Pizza> = [
    new Pizza(/*args*/),
    new Pizza(/*args*/),
    new Pizza(/*args*/)
];

answered Jun 17, 2019 at 14:25

Harun Yilmaz

8,5893 gold badges30 silver badges40 bronze badges

1 Comment

Jgascona Over a year ago

I cannot create like this because Pizza its an Interface, not a class

Collectives™ on Stack Overflow

How can I declare several variables within an array directly in TypeScript

2 Answers 2

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related