Vue封装全局过滤器Filters的步骤

// 封装过滤器
// 过滤器的声明可以有下列多种写法

/
  Number formatting by unit
  like 10000 => 10k
  @param {number} num
  @param {number} digits
  @return {string}
 /
function numberFormatter(num, digits) {
 const si = [
  { value: 1e18, symbol: "E" },
  { value: 1e15, symbol: "P" },
  { value: 1e12, symbol: "T" },
  { value: 1e9, symbol: "G" },
  { value: 1e6, symbol: "M" },
  { value: 1e3, symbol: "k" }
 ];
 for (let i = 0; i < si.length; i++) {
  if (num >= si[i].value) {
   return (num / si[i].value + 0.1).toFixed(digits).replace(/\.0+$|(\.[0-9][1-9])0+$/, '$1') + si[i].symbol
  }
 }
 return num.toString();
}

/
  Number formatting by thousand
  like 10000 => "10,000"
  @param {number} num
  @return {string}
 /
const toThousandFilter = function(num) {
 return (+num || 0).toString().replace(/^-?\d+/g, m => m.replace(/(?=(?!\b)(\d{3})+$)/g, ','))
};

/
  Upper case first char
  like "wenyuan" => "Wenyuan"
  @param {string} string
  @return {string}
 /
const uppercaseFirst = string => {
 return string.charAt(0).toUpperCase() + string.slice(1);
};

export default {
 numberFormatter,
 toThousandFilter,
 uppercaseFirst
};

import filters from "./filters"; // global filters

// register global utility filters
Object.keys(filters).forEach(key => {
 Vue.filter(key, filters[key]);
});

<template>
 <div class="home">
  <img alt="Vue logo" src="../assets/logo.png"/>
  <h1>score{{ score | numberFormatter }}</h1>
  <h1>score{{ score | toThousandFilter }}</h1>
  <h1>username{{ username | uppercaseFirst }}</h1>
 </div>
</template>

<script>
export default {
 name: "home",
 ponents: {},
 data() {
  return {
   score: 1200000,
   username: "wenyuan"
  };
 }
};
</script>