角类不起作用

我正在尝试使用Angular中的类使我的生活更轻松，但到目前为止，它尚不起作用。以下是我的代码和收到的错误：

import { WizardData } from '../models/wizard-data';

export class WizardPage {
    private type: String;
    private data: WizardData;

    public getType(){
        return this.type;
    }

    public setType(type: String){
        this.type = type;
    }

    public getData(){
        return this.data;
    }

    public setData(data: WizardData){
        this.data = data;
    }
}

和

import { Component, OnInit } from '@angular/core';
import { WizardPage } from '../../shared/models/wizard-page';

@Component({
  selector: 'app-wizard-base',
  templateUrl: './wizard-base.component.html',
  styleUrls: ['./wizard-base.component.scss']
})

export class WizardBaseComponent implements OnInit {
  wizardPage: WizardPage = new WizardPage();
  wizardPage.setType("address");

  constructor() { }

  ngOnInit() {}

}

这在行上给出了一个错误

wizardPage.setType("address");

即（CLI）：

ERROR in src/app/wizard/wizard-base/wizard-base.component.ts(14,13): error TS1005: ';' expected.
src/app/wizard/wizard-base/wizard-base.component.ts(14,22): error TS1003: Identifier expected.

在Visual Studio Code中：

[ts] Duplicate identifier 'wizardPage'.
[ts] Subsequent property declarations must have the same type.  Property 'wizardPage' must be of type 'WizardPage', but here has type 'any'.
(property) WizardBaseComponent.wizardPage: WizardPage

有人知道为什么这行不通吗？

谢谢！