import { Component, OnInit } from '@angular/core'; @Component({ selector: 'app-menu', templateUrl: './menu.component.html', styleUrls: ['./menu.component.sass'] }) export class MenuComponent implements OnInit { constructor() { } ngOnInit() { } openMegaMenu(){ let pane = document.getElementsByClassName('cdk-overlay-pane'); [].forEach.call(pane, function (el) { if(el.children.length > 0){ if(el.children[0].classList.contains('mega-menu')){ el.classList.add('mega-menu-pane'); } } }); } }