# Day34 【牙起來】 - Angular 數值處理 - formatNumber, number pipe

用pipe去除前導零

https://stackoverflow.com/questions/40716894/angular2-or-typescript-left-padding-a-string-with-zeros

移除前導零
https://stackoverflow.com/questions/55940899/why-is-angular-number-pipe-not-displaying-if-number-has-a-leading-zero

formatNumber
https://angular.io/api/common/formatNumber

i18n
https://ithelp.ithome.com.tw/articles/10195351

## formatNumber

import { registerLocaleData } from '@angular/common';
import localeZhHant from '@angular/common/locales/zh-Hant';

registerLocaleData(localeZhHant, 'zh-Hant');


...

    let total = formatNumber(..., 'zh-Hant', '1.1-1')

預設是`en-US`，不用註冊也能使用

## i18n

https://www.youtube.com/watch?v=KNTN-nsbV7M

確定專案有安裝localize

> ng add @angular/localize

在`angular.json`底下

"projects":
    "projectName": 
    ...
      "i18n": {
        "sourceLocale": "en-US",
        "locales": {
          "zh-TW": "src/locale/message.zh.xlf"
        }
      },
    ...
      "architect": {
          "build": {
              "options": {
                  "localize": false
                  // "localize": ["zh-TW"]
              }
          }
      }