Ionic 2, how to properly use alert
<p>I am programming using Ionic 2, and I want to show a pop-up alert when a button is clicked.</p>

<p>This is the code in my <em>home.html</em>:</p>

<pre><code>&lt;button (click)='openFilters()'&gt;CLICK&lt;/button&gt;
</code></pre>

<p>And in my <em>home.ts</em></p>

<pre><code>import {Component} from '@angular/core';
import {Page, NavController, Alert} from 'ionic-angular';

@Component({
  templateUrl: 'build/pages/home/home.html'
})
export class HomePage {
  constructor(nav: NavController, alertCtrl: AlertController) {

  }

  openFilters() {
    let alert = this.alertCtrl.create({
        title: 'Low battery',
        subTitle: '10% of battery remaining',
        buttons: ['Dismiss']
    });
    alert.present();
  }
}
</code></pre>

<p>I have read some StackOverflow questions on this topic and tried to implement it like this:</p>

<pre><code>openFilters() {
    let alert:Alert = Alert.create({
        title: 'Low battery',
        subTitle: '10% of battery remaining',
        buttons: ['Dismiss']
    });
    this.nav.present(alert);
  }
</code></pre>

<p>Still, I accomplished nothing; I get errors.</p>