CODEWITHSUNDEEP
angular
jhon.smith
jhon.smith

Reputation: 2043

Unable to understand this Angular method

I saw a piece of code in Angular and i am unable to understand it.

remove_stock({group, index}: {group: FormGroup, index: number}) {
    const control = this.form.get('stock') as FormArray;
    control.removeAt(index);
}

I understand there is a method called remove_stock and since it uses an parenthesis it takes an argument.

But I am not sure about this argument . I know in typescript that anything enclosed in braces is an object and whatever is preceding a colon is the name of the type.

But what i don't get is this

{group, index}: {group: FormGroup, index: number}

Can someone please explain

I have taken this from a screenshot of the course from ultimate Angular and i am stumped. Here is the link to that image

https://i.vimeocdn.com/video/680140010.webp?mw=1500&mh=844&q=70

Thanks

Upvotes: 0

Views: 76

Answers (2)

lupa
lupa

Reputation: 527

First, this syntax have nothing to do with typescript, it's a es6 syntax.
It's called Destructuring assignment, Take a look at this link Destructuring assignment
Take a look at this code:

const user = {
  id: '1',
  name: 'user' 
};

const {id, name} = user;

These lines of code identical as this

const user = {
  id: '1',
  name: 'user' 
};

const id = user.id;
const name = user.name;

And your function above, that will be like this

remove_stock(input: {group: FormGroup, index: number}) {
  const index = input.index;
  const group = input.group;
  const control = this.form.get('stock') as FormArray;
  control.removeAt(index);
}

Upvotes: 2

hernando hurtado hoyos
hernando hurtado hoyos

Reputation: 11

that's a function that removes an element from an array according to the example that I found in this link https://www.cnblogs.com/Answer1215/p/6592580.html a formgroup is created by means of an array

removeStock ({group, index}: {group: FormGroup, index: number}) {
     const control = this.form.get ('stock') as FormArray;
     control.removeAt (index);
   }

two parameters are passed which are the class and the identifier

{group, index}

here the data type of the parameters is expressed

{group: FormGroup, index: number}

a constant is declared that contains the total of the elements const control = this.form.get ('stock') as FormArray;

it removes the element identified by index

control.removeAt (index);

XD That's all I speak Spanish so excuse my writing done on google XD

Upvotes: 1

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