JS 常用代码片段
检查日期是否有效
该方法用于检测给出的日期是否有效：
const isDateValid = (...val) => !Number.isNaN(new Date(...val).valueOf());
isDateValid("December 17, 1995 03:24:00"); // true
计算两个日期之间的间隔
该方法用于检测给出的日期是否有效：
const dayDif = (date1, date2) => Math.ceil(Math.abs(date1.getTime() - date2.getTime()) / 86400000)
dayDif(new Date("2021-11-3"), new Date("2022-2-1")) // 90
查找日期位于一年中的第几天
该方法用于检测给出的日期位于今年的第几天：
const timeFromDate = date => date.toTimeString().slice(0, 8);
timeFromDate(new Date(2021, 11, 2, 12, 30, 0)); // 12:30:00
timeFromDate(new Date()); // 返回当前时间 09:00:00
时间格式化
该方法可以用于将时间转化为hour:minutes:seconds的格式：
const timeFromDate = date => date.toTimeString().slice(0, 8);
timeFromDate(new Date(2021, 11, 2, 12, 30, 0)); // 12:30:00
timeFromDate(new Date()); // 返回当前时间 09:00:00
页面刷新不保留原先位置
保留位置请设置为 auto
if (history.scrollRestoration) {
history.scrollRestoration = 'manual';
}
input限制两位小数
oninput="value = value.match(/^\d*(\.?\d{0,2})/g)[0] || null"
Vue项目修改项目标题
此配置可更改掉index.html的 <%= htmlWebpackPlugin.options.title %>
vue.config.js
module.exports = {
chainWebpack: config => {
config
.plugin('html')
.tap(args => {
args[0].title = '光伏报单'
return args
})
}
}
金额千分位加逗号
比如说 999999999，直接阅读很不直观，格式化后 999,999,999或者999,999,999.00
function formatPrice(price) {
return String(price).replace(/\B(?=(\d{3})+(?!\d))/g, ',');
}
正则匹配电话号码
const isPhone =
/(^([0-9]{3,4}-)?[0-9]{7,8}$)|(^((\(\d{3}\))|(\d{3}\-))?(1[345789]\d{9})$)/;
// 可支持格式1600999、16009999、025-83593004、0311-7046792、18282441800
cookie 操作
class CookieUtil {
static get(name) {
let cookieName = `${encodeURIComponent(name)}=`,
cookieStart = document.cookie.indexOf(cookieName),
cookieValue = null;
if (cookieStart > -1) {
let cookieEnd = document.cookie.indexOf(";", cookieStart);
if (cookieEnd == -1) {
cookieEnd = document.cookie.length;
}
cookieValue = decodeURIComponent(
document.cookie.substring(cookieStart + cookieName.length, cookieEnd)
);
}
return cookieValue;
}
static set(name, value, expires, path, domain, secure) {
let cookieText = `${encodeURIComponent(name)}=${encodeURIComponent(value)}`;
if (expires instanceof Date) {
cookieText += `; expires=${expires.toGMTString()}`;
}
if (path) {
cookieText += `; path=${path}`;
}
if (domain) {
cookieText += `; domain=${domain}`;
}
if (secure) {
cookieText += "; secure";
}
document.cookie = cookieText;
}
static unset(name, path, domain, secure) {
CookieUtil.set(name, "", new Date(0), path, domain, secure);
}
}
// 设置cookie
CookieUtil.set("name", "Nicholas");
CookieUtil.set("book", "Professional JavaScript");
// 读取cookie
alert(CookieUtil.get("name")); // "Nicholas"
alert(CookieUtil.get("book")); // "Professional JavaScript"
// 删除cookie
CookieUtil.unset("name");
CookieUtil.unset("book");
// 设置有路径、域和过期时间的cookie
CookieUtil.set(
"name",
"Nicholas",
"/books/projs/",
"www.wrox.com",
new Date("January 1, 2010")
);
// 删除刚刚设置的cookie
CookieUtil.unset("name", "/books/projs/", "www.wrox.com");
// 设置安全cookie
CookieUtil.set("name", "Nicholas", null, null, null, true);
添加查询字符串
function addQueryStringArg(url, name, value) {
if (url.indexOf("?") == -1) {
url += "?";
} else {
url += "&";
}
url += "${encodeURIComponent(name)=${encodeURIComponent(value)}";
return url;
}
文件大小换算成单位
/**
* 文件大小换算成单位
*
* @param {Number} bytes 大小
* @param {String} units 可选单位，默认metric
* @param {Number} precision 可选位数，数值精度保留几位小数点，默认1
* @return {String} 返回带单位值，byteSize(1580)，输出1.6 kB
*
*/
export const byteSize = (bytes, units = "metric", precision = 1) => {
let value = "",
unit = "";
const base = units === "metric" || units === "metric_octet" ? 1000 : 1024;
const table = [
{
expFrom: 0,
expTo: 1,
metric: "B",
iec: "B",
metric_octet: "o",
iec_octet: "o",
},
{
expFrom: 1,
expTo: 2,
metric: "kB",
iec: "KiB",
metric_octet: "ko",
iec_octet: "Kio",
},
{
expFrom: 2,
expTo: 3,
metric: "MB",
iec: "MiB",
metric_octet: "Mo",
iec_octet: "Mio",
},
{
expFrom: 3,
expTo: 4,
metric: "GB",
iec: "GiB",
metric_octet: "Go",
iec_octet: "Gio",
},
{
expFrom: 4,
expTo: 5,
metric: "TB",
iec: "TiB",
metric_octet: "To",
iec_octet: "Tio",
},
{
expFrom: 5,
expTo: 6,
metric: "PB",
iec: "PiB",
metric_octet: "Po",
iec_octet: "Pio",
},
{
expFrom: 6,
expTo: 7,
metric: "EB",
iec: "EiB",
metric_octet: "Eo",
iec_octet: "Eio",
},
{
expFrom: 7,
expTo: 8,
metric: "ZB",
iec: "ZiB",
metric_octet: "Zo",
iec_octet: "Zio",
},
{
expFrom: 8,
expTo: 9,
metric: "YB",
iec: "YiB",
metric_octet: "Yo",
iec_octet: "Yio",
},
];
for (let i = 0; i < table.length; i++) {
const lower = Math.pow(base, table[i].expFrom);
const upper = Math.pow(base, table[i].expTo);
if (bytes >= lower && bytes < upper) {
const retUnit = table[i][units];
if (i === 0) {
value = String(bytes);
unit = retUnit;
break;
} else {
value = (bytes / lower).toFixed(precision);
unit = retUnit;
break;
}
}
}
return `${value} ${unit}`.trim();
};
防抖
/**
* 防抖 (debounce)将多次高频操作优化为只在最后一次执行
*
* @param {Function} fn 需要防抖函数
* @param {Number} wait 需要延迟的毫秒数
* @param {Boolean} immediate 可选参，设为true，debounce会在wait时间间隔的开始时立即调用这个函数
* @return {Function}
*
*/
export const debounce = (fn, wait, immediate) => {
let timer = null;
return function () {
let args = arguments;
let context = this;
if (immediate && !timer) {
fn.apply(context, args);
}
if (timer) clearTimeout(timer);
timer = setTimeout(() => {
fn.apply(context, args);
}, wait);
};
};
节流
/**
* 节流(throttle)将高频操作优化成低频操作，每隔 100~500 ms执行一次即可
*
* @param {Function} fn 需要防抖函数
* @param {Number} wait 需要延迟的毫秒数
* @param {Boolean} immediate 可选参立即执行，设为true，debounce会在wait时间间隔的开始时立即调用这个函数
* @return {Function}
*
*/
export const throttle = (fn, wait, immediate) => {
let timer = null;
let callNow = immediate;
return function () {
let context = this,
args = arguments;
if (callNow) {
fn.apply(context, args);
callNow = false;
}
if (!timer) {
timer = setTimeout(() => {
fn.apply(context, args);
timer = null;
}, wait);
}
};
};
浮点数精度丢失
/**
* js浮点数计算加减乘除精度损失解决方法
*
* @param {Number} a 数值a
* @param {Number} b 数值b
* @param {String} computeType 加减乘除类型 add加 subtract减 multiply乘 divide除
* @return {Number} 返回计算结果，floatNumber(0.11, 0.03, 'add')
*
*/
export const floatNumber = (a, b, computeType) => {
const isInteger = (obj) => {
return Math.floor(obj) === obj;
};
const toInteger = (floatNum) => {
const ret = { times: 1, num: 0 };
if (isInteger(floatNum)) {
ret.num = floatNum;
return ret;
}
const strfi = floatNum + "";
const dotPos = strfi.indexOf(".");
const len = strfi.substr(dotPos + 1).length;
const times = Math.pow(10, len);
const intNum = parseInt(floatNum * times + 0.5, 10);
ret.times = times;
ret.num = intNum;
return ret;
};
const operation = (a, b, computeType) => {
const o1 = toInteger(a);
const o2 = toInteger(b);
const n1 = o1.num;
const n2 = o2.num;
const t1 = o1.times;
const t2 = o2.times;
const max = t1 > t2 ? t1 : t2;
let result = null;
switch (computeType) {
case "add":
if (t1 === t2) {
// 两个小数位数相同
result = n1 + n2;
} else if (t1 > t2) {
// o1 小数位 大于 o2
result = n1 + n2 * (t1 / t2);
} else {
// o1 小数位 小于 o2
result = n1 * (t2 / t1) + n2;
}
return result / max;
case "subtract":
if (t1 === t2) {
result = n1 - n2;
} else if (t1 > t2) {
result = n1 - n2 * (t1 / t2);
} else {
result = n1 * (t2 / t1) - n2;
}
return result / max;
case "multiply":
result = (n1 * n2) / (t1 * t2);
return result;
case "divide":
result = (n1 / n2) * (t2 / t1);
return result;
}
};
return operation(a, b, computeType);
};
判断当前环境是否是手机端
/**
* 判断当前环境是否是手机端
*
* @return {Boolean} 返回结果
*
*/
export const isMobile = () => {
if (
/Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(
navigator.userAgent
)
) {
return true;
} else {
return false;
}
};
判断当前环境是否是微信环境
/**
* 断当前环境是否是微信环境
*
* @return {Boolean} 返回结果
*
*/
export const isWeixin = () => {
const ua = navigator.userAgent.toLowerCase();
if (ua.match(/MicroMessenger/i) === "micromessenger") {
return true;
} else {
return false;
}
};
检测浏览器是否放大
/**
* 检测浏览器是否放大
*
* @param {Boolean } rsize 是否返回具体放大数值,默认否
* @return {Boolean | Number} 返回结果
*
*/
export const detectZoom = (rsize) => {
let ratio = 0;
const screen = window.screen;
const ua = navigator.userAgent.toLowerCase();
if (window.devicePixelRatio) {
ratio = window.devicePixelRatio;
} else if (~ua.indexOf("msie")) {
if (screen.deviceXDPI && screen.logicalXDPI)
ratio = screen.deviceXDPI / screen.logicalXDPI;
} else if (window.outerWidth && window.innerWidth) {
ratio = window.outerWidth / window.innerWidth;
}
if (ratio) ratio = Math.round(ratio * 100);
return rsize ? ratio : ratio === 100;
};
获取普通地址 url 参数
/**
* 获取普通地址url参数
* 例如：http://localhost:8080/?token=rTyJ7bcRb7KU4DMcWo4216&roleId=512213631174180864
*
* @param {String} name
* @return {Boolean | String} 返回获取值
*
*/
export const getUrlParam = (name) => {
const reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)");
const r = window.location.search.substr(1).match(reg);
if (r != null) return decodeURI(r[2]);
return false;
};
获取 hash 模式地址 url 参数
/**
* 获取hash模式地址url参数
* 例如：http://localhost:8080/#/?token=rTyJ7bcRb7KU4DMcWo4216&roleId=512213631174180864
*
* @param {String} name
* @return {Boolean | String} 返回获取值
*
*/
export const getUrlHashParam = (name) => {
const w = window.location.hash.indexOf("?");
const query = window.location.hash.substring(w + 1);
const vars = query.split("&");
for (let i = 0; i < vars.length; i++) {
const pair = vars[i].split("=");
if (pair[0] == name) {
return pair[1];
}
}
return false;
};
时间戳转换
/**
* 时间戳转换
*
* @param {Number} date 时间戳
* @param {String} fmt 时间显示格式，例如 yyyy-MM-dd HH:mm:ss
* @return {String} fmt 返回转换后的时间 ，formatDate(value, "yyyy-MM-dd hh: mm : ss")
*
*/
export const formatDate = (date, fmt) => {
date = new Date(date);
if (isNaN(date.getDate())) return date;
if (/(y+)/.test(fmt)) {
fmt = fmt.replace(
RegExp.$1,
(date.getFullYear() + "").substr(4 - RegExp.$1.length)
);
}
let o = {
"M+": date.getMonth() + 1,
"d+": date.getDate(),
"h+": date.getHours(),
"m+": date.getMinutes(),
"s+": date.getSeconds(),
};
for (let k in o) {
if (new RegExp(`(${k})`).test(fmt)) {
let str = o[k] + "";
fmt = fmt.replace(
RegExp.$1,
RegExp.$1.length === 1 ? str : ("00" + str).substr(str.length)
);
}
}
return fmt;
};
时间戳转换成什么之前
/**
* 时间戳转换成什么之前
*
* @param {Number} times 时间戳
* @return {String} 返回结果，timeAgoLabel(1606273724459) 输出：刚刚
*
*/
export const timeAgoLabel = (times) => {
let nowTimes = new Date().getTime();
let diffSecond = (nowTimes - times) / 1000;
let agoLabel = "";
if (diffSecond < 60) {
agoLabel = "刚刚";
} else if (diffSecond < 60 * 60) {
agoLabel = Math.floor(diffSecond / 60) + "分钟前";
} else if (diffSecond < 60 * 60 * 24) {
agoLabel = Math.floor(diffSecond / 3600) + "小时前";
} else if (diffSecond < 60 * 60 * 24 * 30) {
agoLabel = Math.floor(diffSecond / (3600 * 24)) + "天前";
} else if (diffSecond < 3600 * 24 * 30 * 12) {
agoLabel = Math.floor(diffSecond / (3600 * 24 * 30)) + "月前";
} else {
agoLabel = Math.floor(diffSecond / (3600 * 24 * 30 * 12)) + "年前";
}
return agoLabel;
};
npm 淘宝镜像
npm install --registry=https://registry.npm.taobao.org
元素在页面中的偏移量
把 offsetLeft 和 offsetTop 属性分别与 offsetParent 的相同属性相加，一直加到根元素。
function getElementLeft(element) {
let actualLeft = element.offsetLeft;
let current = element.offsetParent;
while (current !== null) {
actualLeft += current.offsetLeft;
current = current.offsetParent;
}
return actualLeft;
}
function getElementTop(element) {
let actualTop = element.offsetTop;
let current = element.offsetParent;
while (current !== null) {
actualTop += current.offsetTop;
current = current.offsetParent;
}
return actualTop;
}
查询 url 参数
let getQueryStringArgs = function () {
// 取得没有开头问号的查询字符串
let qs = location.search.length > 0 ? location.search.substring(1) : "",
// 保存数据的对象
args = {};
// 把每个参数添加到args对象
for (let item of qs.split("&").map((kv) => kv.split("="))) {
let name = decodeURIComponent(item[0]),
value = decodeURIComponent(item[1]);
if (name.length) {
args[name] = value;
}
}
return args;
};
洗牌算法
class SuperArray extends Array {
shuffle() {
// 洗牌算法
for (let i = this.length - 1; i > 0; i--) {
const j = Math.floor(Math.random() * (i + 1));
[this[i], this[j]] = [this[j], this[i]];
}
}
}
let a = new SuperArray(1, 2, 3, 4, 5);
console.log(a instanceof Array); // true
console.log(a instanceof SuperArray); // true
console.log(a); // [1, 2, 3, 4, 5]
a.shuffle();
console.log(a); // [3, 1, 4, 5, 2]
检查两个以上的值是否相等
function recursivelyCheckEqual(x, ...rest) {
return (
Object.is(x, rest[0]) && (rest.length < 2 || recursivelyCheckEqual(...rest))
);
}
生成任意位数随机数(数字)
/**
* 生成任意位数随机数(数字)
*
* @param {Number} n 可选长度位数
* @return {Number} 返回随机值
*
*/
export const randomNumber = (n) => {
let rnd = "";
for (let i = 0; i < n; i++) {
rnd += Math.floor(Math.random() * 10);
}
return rnd;
};
生成随机ID
/**
* 随机生成一个自定义长度，不重复的字母加数字组合，可用来做id标识
*
* @param {Number} randomLength 可选长度位数，默认10
* @return {String} 返回随机值
*
*/
export const randomId =(randomLength = 10) =>{
return Number(Math.random().toString().substr(3,randomLength) + Date.now()).toString(36)
},
数组去重
/**
* js数组去重(复杂数据有ID的情况下)
* 方式一(hash)
*
* @param {Array} repeatArray 含重复数据的数组
* @return {Array} 返回去重后的数据
*
*/
export const noRepeatArrayHash = (repeatArray) => {
const hash = {};
const temp = [];
for (let i = 0; i < repeatArray.length; i++) {
if (!hash[repeatArray[i].id]) {
hash[repeatArray[i].id] = true;
temp.push(repeatArray[i]);
}
}
return temp;
};
/**
* js数组去重(复杂数据有ID的情况下)
* 方式二(hash + reduce)
*
* @param {Array} repeatArray 含重复数据的数组
* @return {Array} 返回去重后的数据
*
*/
export const noRepeatArrayReduce = (repeatArray) => {
const hash = {};
return repeatArray.reduce(function (accumulator, currentValue) {
if (!hash[currentValue.id]) {
hash[currentValue.id] = true;
accumulator.push(currentValue);
}
return accumulator;
}, []);
};
从一组整数中随机选择一个数
function selectFrom(lowerValue, upperValue) {
let choices = upperValue - lowerValue + 1;
return Math.floor(Math.random() * choices + lowerValue);
}
let num = selectFrom(2, 10);
console.log(num); // 2~10范围内的值，其中包含2和10
// 使用
let colors = ["red", "green", "blue", "yellow", "black", "purple", "brown"];
let color = colors[selectFrom(0, colors.length - 1)];
查找字符串出现位置
let stringValue = "Lorem ipsum dolor sit amet, consectetur adipisicing elit";
let positions = new Array();
let pos = stringValue.indexOf("e");
while (pos > -1) {
positions.push(pos);
pos = stringValue.indexOf("e", pos + 1);
}
console.log(positions); // [3,24,32,35,52]
axios 封装
import axios from "axios";
import { MessageBox, Message } from "element-ui";
import store from "@/store";
// import { getToken } from '@/utils/auth'
// create an axios instance
const service = axios.create({
baseURL: process.env.VUE_APP_BASE_API, // url = base url + request url
// withCredentials: true, // send cookies when cross-domain requests
timeout: 15000, // request timeout
});
service.defaults.headers.post["Content-Type"] =
"application/x-www-form-urlencoded"; // 设置post请求头
// request interceptor
// service.interceptors.request.use(
// config => {
// // do something before request is sent
// if (store.getters.token) {
// // let each request carry token
// // ['X-Token'] is a custom headers key
// // please modify it according to the actual situation
// config.headers['X-Token'] = getToken()
// }
// return config
// },
// error => {
// // do something with request error
// console.log(error) // for debug
// return Promise.reject(error)
// }
// )
// response interceptor
service.interceptors.response.use(
/**
* If you want to get http information such as headers or status
* Please return response => response
*/
/**
* Determine the request status by custom code
* Here is just an example
* You can also judge the status by HTTP Status Code
*/
(response) => {
const res = response.data;
// if the custom code is not 20000, it is judged as an error.
if (res.code == 0) {
if (res.msg !== "没有数据!") {
Message({
message: res.msg || "Error",
type: "error",
duration: 5 * 1000,
});
}
// 50008: Illegal token; 50012: Other clients logged in; 50014: Token expired;
if (res.code === 50008 || res.code === 50012 || res.code === 50014) {
// to re-login
MessageBox.confirm(
"You have been logged out, you can cancel to stay on this page, or log in again",
"Confirm logout",
{
confirmButtonText: "Re-Login",
cancelButtonText: "Cancel",
type: "warning",
}
).then(() => {
store.dispatch("user/resetToken").then(() => {
location.reload();
});
});
}
return res;
// return Promise.reject(new Error(res.msg || 'Error'))
} else {
return res;
}
},
(error) => {
console.log("err" + error); // for debug
Message({
message: error.message,
type: "error",
duration: 5 * 1000,
});
return Promise.reject(error);
}
);
export default service;
小程序 http 封装
import { config } from "../config/config";
import { promisic } from "../utils/util";
class Http {
static async request({ url, data, method = "GET" }) {
const res = await promisic(wx.request)({
url: `${config.apiBaseUrl}${url}`,
data,
method,
header: {
appKey: config.appkey,
},
});
return res.data;
}
}
export { Http };
下拉加载更多（分页）
import { Http } from "./http";
class Paging {
start;
count;
req;
locker = false;
url;
moreData = true;
accumulator = [];
constructor(req, count = 10, start = 0) {
this.start = start;
this.count = count;
this.req = req;
this.url = req.url;
}
async getMoreData() {
if (!this.moreData) {
return;
}
if (!this._getLocker) {
return;
}
const data = await this._actualGetData();
this._releaseLocker();
return data;
}
async _actualGetData() {
const req = this._getCurrentReq();
let paging = await Http.request(req);
if (!paging) {
return null;
}
if (paging.total === 0) {
return {
empty: true,
items: [],
moreData: false,
accumulator: [],
};
}
this.moreData = Paging._moreData(paging.total_page, paging.page);
if (this.moreData) {
this.start += this.count;
}
this._accumulate(paging.items);
return {
empty: false,
items: paging.items,
moreData: this.moreData,
accumulator: this.accumulator,
};
}
static _moreData(totalPage, pageNum) {
return pageNum < totalPage - 1;
}
_accumulate(items) {
this.accumulator = this.accumulator.concat(items);
}
_getCurrentReq() {
let url = this.url;
const params = `start=${this.start}&count=${this.count}`;
if (url.includes("?")) {
url += "&" + params;
} else {
url += "?" + params;
}
this.req.url = url;
return this.req;
}
_getLocker() {
if (this.locker) {
return false;
}
this.locker = true;
return true;
}
_releaseLocker() {
this.locker = false;
}
}
export { Paging };
状态机
三种状态不停切换
let state = function* () {
while (1) {
yield "A";
yield "B";
yield "C";
}
};
let status = state();
console.log(status.next());
console.log(status.next());
console.log(status.next());
console.log(status.next());
console.log(status.next());
抽奖
let draw = function (count) {
//具体抽奖逻辑
console.info(`剩余${count}次`);
};
let residue = function* (count) {
while (count > 0) {
count--;
yield draw(count);
}
};
let star = residue(5);
let btn = document.createElement("button");
btn.id = "start";
btn.textContent = "抽奖";
document.body.appendChild(btn);
document.getElementById("start").addEventListener(
"click",
function () {
star.next();
},
false
);
长轮询
// 长轮询
let ajax = function* () {
yield new Promise(function (resolve, reject) {
setTimeout(function () {
resolve({ code: 0 });
}, 200);
});
};
let pull = function () {
let genertaor = ajax();
let step = genertaor.next();
step.value.then(function (d) {
if (d.code != 0) {
setTimeout(function () {
console.info("wait");
pull();
}, 1000);
} else {
console.info(d);
}
});
};
pull();
url 拼接
url += (url.indexOf("?") < 0 ? "?" : "&") + param(data);
function param() {
let url = "";
for (let k in data) {
let value = data[k] !== undefined ? data[k] : "";
url += `&${k}=${encodeURIComponent(value)}`;
}
return url ? url.substring(1) : "";
}
获取最大 Z-index 值
function getMaxZIndex() {
var maxZ = Math.max.apply(
null,
$.map($("body *"), function (e, n) {
if ($(e).css("position") != "static") {
return parseInt($(e).css("z-index")) || -1;
}
})
);
return maxZ;
}
jq 引入
(function ($) {
$(function () {});
})(jQuery);
(function($){...})(jQuery)用来定义一些需要预先定义好的函数
$(function(){ })用来在 DOM 加载完成之后运行\执行那些预行定义好的函数.
- 避免全局依赖；
- 避免第三方破坏；
- 兼容 jquery 操作符"$"和 jquery；
乱序排列
function getRandomInt(min, max) {
return Math.floor(Math.random() * (max - min + 1) + min);
}
export function shuffle(arr) {
for (let i = 0; i < arr.length; i++) {
let j = getRandomInt(0, i);
let t = arr[i];
arr[i] = arr[j];
arr[j] = t;
}
return arr;
}
生成随机数
const chars = [
"0",
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8",
"9",
"A",
"B",
"C",
"D",
"E",
"F",
"G",
"H",
"I",
"J",
"K",
"L",
"M",
"N",
"O",
"P",
"Q",
"R",
"S",
"T",
"U",
"V",
"W",
"X",
"Y",
"Z",
];
const random = function generateMixed(n) {
var res = "";
for (var i = 0; i < n; i++) {
var id = Math.ceil(Math.random() * 35);
res += chars[id];
}
return res;
};
封装 promise
将小程序内置非 promise API 转换为 promise
const promisic = function (func) {
return function (params = {}) {
return new Promise((resolve, reject) => {
const args = Object.assign(params, {
success: (res) => {
resolve(res);
},
fail: (error) => {
reject(error);
},
});
func(args);
});
};
};
点击复制
第一种
function copyUrl1(e) {
var copyText = $("#copyUrl");
copyText.select();
document.execCommand("Copy");
FoxUI.alert("已复制,马上去邀请小伙伴吧!");
}
第二种
/**
* 将一个字符串复制到剪贴板
* @param {String} str 复制的内容
* @return {String} 直接粘贴， copyToClipboard('将一个字符串复制到剪贴板')
*
*/
export const copyToClipboard = (str) => {
const el = document.createElement("textarea");
el.value = str;
el.setAttribute("readonly", "");
el.style.position = "absolute";
el.style.left = "-9999px";
document.body.appendChild(el);
const selected =
document.getSelection().rangeCount > 0
? document.getSelection().getRangeAt(0)
: false;
el.select();
document.execCommand("copy");
document.body.removeChild(el);
if (selected) {
document.getSelection().removeAllRanges();
document.getSelection().addRange(selected);
}
};
平滑滚动到页面顶部
/**
* 平滑滚动到页面顶部
*
*/
export const scrollToTop = () => {
const c = document.documentElement.scrollTop || document.body.scrollTop;
if (c > 0) {
window.requestAnimationFrame(scrollToTop);
window.scrollTo(0, c - c / 8);
}
};
记录上次点击
var pre;
$(".un_bt").bind("click", function () {
if (this !== pre) {
var preType = $(pre).find(".bttype").text() || un_bt_type;
}
pre = this;
});
