How to check if javascript array holds property with specific value, if so returns true

Question

I have a select - option in angular, and I need to check values that have same id as id in database, so I have tried something like this:

isDropdownValueSelected(amf: ApplicationModuleForm): boolean {
    for (let i = 0; i < this.role.applicationForms.length; i++) {
      if (this.role.applicationForms[i].id == amf.id) {
        return true;
      }
      else {
        return false;
      }
    }
 }

My angular part:

<div class="col-lg-9">
     <select id="applicationModuleFormSelect" name="applicationModuleFormSelect" class="form-control multiselect-select-all" multiple="multiple" data-fouc>
        <option *ngFor="let amf of appModuleForms;" [value]="amf.id" [selected]="isDropdownValueSelected(amf)">{{amf.title}}</option>
     </select>
</div>

So basically there I wanted to loop for each id in option and if I found similar in my array I would return true, because array this.role.applicationForms holds values from database, but unfortunatelly this does not works, nothing is selected in dropdown and I tested with console log it says only 1 value exist even if there are 3..

Thanks guys Cheers

related: stackoverflow.com/questions/237104/…

tanaydin
– tanaydin

2019-02-05 10:40:40 +00:00
Commented Feb 5, 2019 at 10:40 — tanaydin
– tanaydin, Commented Feb 5, 2019 at 10:40

Nina Scholz · Accepted Answer · 2019-02-05 10:35:59Z

1

Maybe you need to move the false value to the end for returning, because every return statement ends the function.

isDropdownValueSelected(amf: ApplicationModuleForm): boolean {
    for (let i = 0; i < this.role.applicationForms.length; i++) {
        if (this.role.applicationForms[i].id == amf.id) {
            return true;
        }
    }
    return false;
}

answered Feb 5, 2019 at 10:35

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

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

Comments

Ryan Walls · Accepted Answer · 2019-02-05 11:11:49Z

1

This function only works when the id of the first element is matched, because you're returning the value on every check.

You should update the code to be like this:

isDropdownValueSelected(amf: ApplicationModuleForm): boolean {
    for (let i = 0; i < this.role.applicationForms.length; i++) {
        if (this.role.applicationForms[i].id == amf.id) {
            return true;
        }
    }
    return false;
}

edited Feb 5, 2019 at 11:11

Ryan Walls

2012 silver badges13 bronze badges

answered Feb 5, 2019 at 10:38

Ankur Jain

2211 silver badge6 bronze badges

Comments

ZER0 · Accepted Answer · 2019-02-05 10:42:17Z

0

Assuming applicationForms is an array, you can use the method some:

isDropdownValueSelected(amf: ApplicationModuleForm): boolean {
  return this.role.applicationForms.some(({id}) => id === amf.id);
}

answered Feb 5, 2019 at 10:42

ZER0

25.5k5 gold badges53 silver badges57 bronze badges

Comments

jo_va · Accepted Answer · 2019-02-05 10:54:01Z

0

Use the some operator instead of looping on your elements:

isDropdownValueSelected(amf: ApplicationModuleForm): boolean {
    return this.role.applicationForms.some(e => e.id === amf.id);
}

answered Feb 5, 2019 at 10:54

jo_va

14.1k3 gold badges25 silver badges49 bronze badges

Comments

Joe Belladonna · Accepted Answer · 2019-02-05 11:04:18Z

0

You do not need for loop:

isDropdownValueSelected(amf: ApplicationModuleForm): boolean {
            if (this.role.applicationForms.find(x => x.id == amf.id)) {
                return true;
            }
            else {
                return false;
            }
        }

answered Feb 5, 2019 at 11:04

Joe Belladonna

1,35914 silver badges20 bronze badges

Collectives™ on Stack Overflow

How to check if javascript array holds property with specific value, if so returns true

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related