import { Component, OnInit } from '@angular/core'; import * as $ from 'jquery'; declare const window: any; @Component({ selector: 'app-header', templateUrl: './header.component.html', styleUrls: ['./header.component.scss'] }) export class HeaderComponent implements OnInit { constructor() { $(window).scroll(function(){ var custom = $('.navbar'), scroll = $(window).scrollTop(); console.log(scroll); if(scroll > 1) custom.addClass("nav_color"); else custom.removeClass("nav_color"); }); } ngOnInit() { } }