Html Page
<ion-card-content>
<form [formGroup]="formgroup">
<ion-item>
<ion-label>
Name
</ion-label>
<ion-input type="text" formControlName="name"></ion-input>
</ion-item>
<ion-item *ngIf ="name.hasError('required') && name.touched">
<p> * Name is Required</p>
</ion-item>
<ion-item>
<ion-label>
Email
</ion-label>
<ion-input type="text" formControlName="email"></ion-input>
</ion-item>
<ion-item *ngIf ="email.hasError('required') && name.touched">
<p> *Email is Required</p>
</ion-item>
</form>
</ion-card-content>
</ion-card>
<button ion-button block round outline default color="dark">
<ion-icon slot="start" name="person-add"></ion-icon>
Add Friend
</button>
TS Page
import { Component } from '@angular/core';
import { IonicPage, NavController, NavParams } from 'ionic-angular';
import { FormBuilder, FormGroup, Validators, AbstractControl} from '@angular/forms';
@IonicPage()
@Component({
selector: 'page-mainreferpg',
templateUrl: 'mainreferpg.html',
})
export class MainreferpgPage {
formgroup:FormGroup;
name: AbstractControl;
email: AbstractControl;
constructor(public navCtrl: NavController, public navParams: NavParams, public formbuilder:FormBuilder) {
this.formgroup = formbuilder.group({
name:['',[ Validators.required, Validators.maxLength(4 )]],
email:['',Validators.compose([Validators.maxLength(70), Validators.pattern('^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$'), Validators.required])]
});
this.name = this.formgroup.controls['name'];
this.email = this.formgroup.controls['email'];
}