p4.component.ts

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

@Component({
  selector: 'app-p4',
  templateUrl: './p4.component.html',
  styleUrls: ['./p4.component.css']
})
export class P4Component implements OnInit {

  number = '';
  value2: any;
  test: number;
  test2: number;
  test3 = '';

  checkNumber(test): void {
    console.log(test);

    if (test <= 0 || test === undefined) {
      alert('必須輸入大於0的數字');
    } else {
      alert('輸入正確');
    }
  }

  checkNumber2(test2): void {
    console.log(test2);

    if (test2 === undefined || test2 === null) {
      alert('只能輸入數字');
    } else {
      alert('輸入正確');
    }
  }

  checkNumber3(test3): void {
    console.log(test3);

    if (test3.match(/([A-z])/g).length === 2 && (test3.match(/([0-9])/g).length === 3)) {
      alert('輸入正確');
    } else {
      alert('只能輸入英文兩碼 + 數字三碼');
    }
  }

  // addNumber(inputRef: HTMLInputElement): void {
  //   console.log(inputRef.value);
  //   inputRef.value = '';

  //   this.value2 = +inputRef.value;

  //   if (this.value2 <= 0) {
  //     alert('請輸入大於0的數字');
  //   } else {
  //   alert('輸入正確');
  //   }
  // }


  constructor() { }

  ngOnInit() {
  }

}