我该如何解决这个错误？天数：NaN 年NaN 月NaN 周NaN 天NaN 分钟NaN 秒

Question

我正在做一个离子项目，遇到这个错误。我有一个按钮，我想要打印用户 select

的日期

我的代码

age.component.ts

import { Component, OnInit } from '@angular/core';
import * as moment from'moment';
@Component({
 .....
})
export class AgeComponent implements OnInit {
dob:any = '' ;
myDate = {
  years: 0,
  months:0,
  weeks:0,
  days:0,
  minutes:0,
  seconds:0,
}
  constructor() { }
  calculateAge(){
      let todaysDate = moment(new Date());
      let dob = moment( new Date(this.dob) );
      let duration = moment.duration(todaysDate.diff(dob));
      this.myDate.years = duration.years();
      this.myDate.months = Math.floor(duration.asMonths());
      this.myDate.weeks = Math.floor(duration.asWeeks());
      this.myDate.days = Math.floor(duration.asDays());
      this.myDate.minutes = Math.floor(duration.asMinutes());
      this.myDate.seconds = Math.floor(duration.asSeconds());
  }
    }

这是我的 age.component.html 代码

<ion-datetime class="datetime" [(ngModel)]="dob" pickerFormat="MMM DD YYYY" 
displayFormat="MMM DD, YYYY" min="1950-01-01" max="2050-01-01"></ion-datetime>
<ion-button (click)="calculateAge()" >Calculate</ion-button>
  <span>{{myDate.years}} years</span>
  <span>{{myDate.months}} months</span>
  <span>{{myDate.weeks}} weeks</span>
  <span>{{myDate.days}} days</span>
  <span>{{myDate.minutes}} minutes</span>
  <span>{{myDate.seconds}} seconds</span>

Answer 1

NaN 错误只会在您不 select 来自 ion-datetime 的任何日期时发生。要解决该问题，您只需将变量 let dob 中的条件添加到 let dob = moment( new Date(this.dob ? this.dob : todaysDate));

TS

calculateAge(){
      let todaysDate = moment(new Date());
      let dob = moment( new Date(this.dob ? this.dob : todaysDate)); <-- add condition here
      let duration = moment.duration(todaysDate.diff(dob));
      this.myDate.years = duration.years();
      this.myDate.months = Math.floor(duration.asMonths());
      this.myDate.weeks = Math.floor(duration.asWeeks());
      this.myDate.days = Math.floor(duration.asDays());
      this.myDate.minutes = Math.floor(duration.asMinutes());
      this.myDate.seconds = Math.floor(duration.asSeconds());
}

这是sample

我该如何解决这个错误？天数：NaN 年NaN 月NaN 周NaN 天NaN 分钟NaN 秒

How can I fix this error ? days: NaN yearsNaN monthsNaN weeksNaN daysNaN minutesNaN seconds

time

date

ionic-framework

angular