表单中的Angular2访问值

Question

I have a problem getting an id from my form.

this.myForm looks like this @Input() public myForm: FormGroup;

it is a input from another .ts file

this is the structure of the form:
myForm
- firstname
- lastname
- Email
--Tags (FormArray)
---id (FormGroup)

I want to get access to the id and fill this.selectedTagList with all the tags from one user and this is what i'm trying to do:

const control: FormArray = <FormArray>this.myForm.controls[ 'tags' ];
control.controls.forEach(tag=> {
this.selectedTagList.push(this.tagList.find(tag.value.id));
});

if i console.log(this.myForm) i get this structure:

console.log(control.controls), 'controls' from the code above:

but when i do console.log(control.controls.length) i get 0. Or when i do console.log(control.controls[0]) i get undefined.

I have no idea where the FormGroup objects went or why it says Array[0] with 4 FormGroup objects in it.

Answer 1

试试console.log（this.myForm.controls ['id']）;

Answer 2

Try the same as John said, what you have is not a number indexed array, but you have a object with named indexes (like associative array).

In JavaScript, arrays use numbered indexes. In JavaScript, objects use named indexes.Where names indexes is the same as associative array.

For more info see: https://www.w3schools.com/js/js_arrays.asp