write a word

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.scss']
})
export class AppComponent implements OnInit {
  slogan: string = '';
  slogans: string[] = ['Hello', 'World'];
  activeSloganIndex: number = 0;

  constructor() { }

  ngOnInit() {
    this.addWordToSlogan(this.slogans[this.activeSloganIndex]);
  }

  addWordToSlogan(word) {
    this.slogan = '';

    for (let i = 0; i < word.length; i++) {
      setTimeout(() => {
        this.slogan += word[i];

        if (i === word.length - 1) {
          setTimeout(() => this.removeWordFromSlogan(), 2000);
        }
      }, i * 350);
    }
  }

  removeWordFromSlogan() {
    for (let i = 0; i < this.slogan.length; i++) {
      setTimeout(() => {
        this.slogan = this.slogan.substr(0, this.slogan.length - 1);

        if (!this.slogan) {
          this.activeSloganIndex++;

          if (this.activeSloganIndex === this.slogans.length) {
            this.activeSloganIndex = 0;
          }

          setTimeout(() => this.addWordToSlogan(this.slogans[this.activeSloganIndex]), 1000);
        }
      }, i * 200);
    }
  }
}