js工具函数总结

获取浏览器 Cookie 的值

export const cookie = name => `; ${document.cookie}`.split(`; ${name}=`).pop().split(';').shift();

将 RGB 转换为十六进制

export const rgbToHex = (r, g, b) => "#" + ((1 << 24) + (r << 16) + (g << 8) + b).toString(16).slice(1);

复制到剪贴板

export const copyToClipboard = (text) => navigator.clipboard.writeText(text);

检查日期是否有效

const isDateValid = (...val) => !Number.isNaN(new Date(...val).valueOf());

找出一年中的某一天

export const dayOfYear = (date) => Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);

将字符串首字母大写

export const capitalize = str => str.charAt(0).toUpperCase() + str.slice(1)

计算两天之间相差的天数

export const dayDif = (date1, date2) => Math.ceil(Math.abs(date1.getTime() - date2.getTime()) / 86400000)

清除所有 Cookie

export const clearCookies = document.cookie.split(';').forEach(cookie => document.cookie = cookie.replace(/^ +/, '').replace(/=.\*/, `=;expires=${new Date(0).toUTCString()};path=/`));

生成随机十六进制

const randomHex = () => `#${Math.floor(Math.random() * 0xffffff).toString(16).padEnd(6, "0")}`;

从 URL 获取查询参数

const getParameters = (URL) => {
  URL = JSON.parse('{"' + decodeURI(URL.split("?")[1]).replace(/"/g, '\\"').replace(/&/g, '","').replace(/=/g, '":"') +'"}');
  return JSON.stringify(URL);
};

求平均值

const average = (...args) => args.reduce((a, b) => a + b) / args.length;

回到顶部

const goToTop = () => window.scrollTo(0, 0);

检查数组是否为空

const isNotEmpty = arr => Array.isArray(arr) && arr.length > 0;

打乱数组

const shuffleArray = (arr) => arr.sort(() => 0.5 - Math.random());

检测用户是否处于暗模式

const isDarkMode = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches

343123.23 转化为「343,123.23」

function format(number) {
  return number && number.replace(/(?!^)(?=(\d{3})+\.)/g, ",");
}

获取文件扩展名

function getFileExtension(filename) {
  return filename.slice(((filename.lastIndexOf(".") - 1) >>> 0) + 2);
}