// 转小写
let lower = value => value.toLowerCase();
// 转大写
let upper = value => value.toUpperCase();
let currencyStyle = (value, style) => { // 货币格式
  /**
   * style: 
   *   currency：货币
   *   number： 数字格式
   */
  if(style == 'number') { // 数字格式
    return parseFloat(value.replace(/[^\d\.-]/g, ""));
  } else { // 货币格式, 并保留2位小数
    var n = 2;
    value = parseFloat((value + "").replace(/[^\d\.-]/g, "")).toFixed(n) + "";
    var l = value.split(".")[0].split("").reverse(),
      r = value.split(".")[1];
    var t = "";
    for (var i = 0; i < l.length; i++) {
      t += l[i] + ((i + 1) % 3 == 0 && (i + 1) != l.length "," : "");
    }
    return t.split("").reverse().join("") + "." + r;
  }
}
export {
  lower,
  upper,
  currencyStyle
}

import Vue from 'vue'
import App from './App.vue'
import * as filters from './assets/filters'
Object.keys(filters).forEach(key => {
 Vue.filter(key, filters[key])
})
Vue.config.productionTip = false
new Vue({
 render: h => h(App),
}).$mount('#app')

<template>
 <div id="app">
  <p>{{ num1 | currencyStyle('currency') }}</p>
  <p>{{ num2 | currencyStyle('number') }}</p>
  <p>{{ msg1 | lower }}</p>
  <p>{{ msg2 | upper }}</p>
 </div>
</template>
<script>
export default {
 name: 'app',
 data() {
  return {
   num1: 123456,
   num2: '123,456',
   msg1: 'ABC',
   msg2: 'def'
  }
 }
}
</script>