set default value when radio button is selected

Question

i have a form with radio button, if user selects no then a default value s'0' should be added to the input tag, i tried setting 0 as a default value when form is been loaded using value='0' but this value is not reflected when the form is loaded.

     <form #form="ngForm" (ngSubmit)="modifyMilkForm(form)" novalidate>
        <ion-row>
                    <ion-col style="text-align: right;">
                         <ion-label><b>Today Received :</b></ion-label>
                    </ion-col>

                    <ion-col>
                        <ion-list radio-group name="checkBox" [(ngModel)]="autoManufacturers">
                            <ion-item>
                                <ion-label>Yes</ion-label>
                                <ion-radio  [value]="true"></ion-radio>
                            </ion-item>
                            <ion-item>
                                <ion-label>No</ion-label>
                                <ion-radio  [value]="false"></ion-radio>
                            </ion-item>
                        </ion-list>
                    </ion-col>
                </ion-row>

                <ion-row>
                    <ion-col style="text-align: right;" >
                         <ion-label><b>Price :</b></ion-label>
                    </ion-col>
                    <ion-col>
                         <ion-item name="price" [(ngModel)]="enteredPrice" required> 
                            <ion-input type="number" value="0"  placeholder="Number"></ion-input>
                        </ion-item>  
                    </ion-col>
                </ion-row>
<button small [disabled]=!form.valid style="text-transform: none" ion-button type="submit" value="Submit" small>Submit</button>
</form>

could someone help me to fix this

Answer 1

Here it is

 class initRadioGroup { selectedRadio = {"value":"N"}; } 

 <md-radio-group class="form-control" [(ngModel)]="selectedRadio.value" id="radioList" formControlName="selectedRadio"> <md-radio-button [value]="'N'">N</md-radio-button> <md-radio-button [value]="'M'">M</md-radio-button> </md-radio-group>