Angular reactive form with conditionally pre-set data

student-form.ts

import { Component, OnInit } from '@angular/core';
import { NavParams } from 'ionic-angular';
import { FormBuilder, FormGroup, Validators } from '@angular/forms'; 
import { StudentsProvider } from '../../../providers/students-provider';

@Component({
    selector: 'student-form',
    templateUrl: 'student-form.html'
})
export class StudentForm implements OnInit {

    private studentId: number;
    private student: any;
    private studentForm: FormGroup;

    constructor(
        private studentsProvider: StudentsProvider,
        private navParams: NavParams,
        private fb: FormBuilder
    ) {}

    ngOnInit() {
        this.studentId = this.navParams.get('studentId');
        this.student = this.studentId !== null ? this.studentsProvider.getStudent(this.studentId) : null;

        this.studentForm = this.fb.group({
            firstName: [''],
            lastName: [''],
            birthday: [''],
            gradeLevel: [''],
            schoolYear: ['']
        });

        if (typeof this.student !== undefined) {

            this.studentForm.setValue({
                firstName: this.student.firstName,
                lastName: this.student.lastName,
                birthday: this.student.birthday,
                gradeLevel: this.student.gradeLevel,
                schoolYear: this.student.schoolYear
            });
        }
    }

}

students-provider.ts

import { Injectable } from '@angular/core';
import 'rxjs/add/operator/map';


@Injectable()
export class StudentsProvider {

  private students: any[] = [
    {
      firstName: 'JC',
      lastName: 'Denton',
      birthday: '',
      gradeLevel: '3rd',
      schoolYear: '2016-2017'
    },
    {
      firstName: 'Paul',
      lastName: 'Denton',
      birthday: '',
      gradeLevel: '3rd',
      schoolYear: '2016-2017'
    },
    {
      firstName: 'Bob',
      lastName: 'Page',
      birthday: '',
      gradeLevel: '3rd',
      schoolYear: '2016-2017'
    }
  ];

  constructor() {
  }

  getStudents() {
    return this.students;
  }

  getStudent(id) {
    return this.students[id];
  }

}