本文已经过原作者 YoussefZidan 授权翻译。
randomNumber()
获取指定区间的随机数。
- **
- * 在最小值和最大值之间生成随机整数。
- * @param {number} min Min number
- * @param {number} max Max Number
- */
- export const randomNumber = (min = 0, max = 1000) =>
- Math.ceil(min + Math.random() * (max - min));
- // Example
- console.log(randomNumber()); // 97
capitalize()
将字符串的第一个字母变为大写。
- /**
- * Capitalize Strings.
- * @param {string} s String that will be Capitalized
- */
- export const capitalize = (s) => {
- if (typeof s !== "string") return "";
- return s.charAt(0).toUpperCase() + s.slice(1);
- }
- // Example
- console.log(capitalize("cat")); // Cat
truncate();
这对于长字符串很有用,特别是在表内部。
- /**
- * 截断字符串....
- * @param {string} 要截断的文本字符串
- * @param {number} 截断的长度
- */
- export const truncate = (text, num = 10) => {
- if (text.length > num) {
- return `${text.substring(0, num - 3)}...`
- }
- return text;
- }
- // Example
- console.log(truncate("this is some long string to be truncated"));
- // this is...
toTop();
滚到到底部,可以通过 behavior 属性指定滚动速度状态。
- /**
- * Scroll to top
- */
- export const toTop = () => {
- window.scroll({ top: 0, left: 0, behavior: "smooth" });
- };
softDeepClone()
这个方法是经常被用到的,因为有了它,我们可以深度克隆嵌套数组或对象。
不过,这个函数不能与new Date()、NaN、undefined、function、Number、Infinity等数据类型一起工作。
你想深度克隆上述数据类型,可以使用 lodash 中的 cloneDeep() 函数。
- /**
- * Deep cloning inputs
- * @param {any} input Input
- */
- export const softDeepClone= (input) => JSON.parse(JSON.stringify(input));
appendURLParams() & getURLParams()
快速添加和获取查询字符串的方法,我通常使用它们将分页元数据存储到url。
- /**
- * Appen query string and return the value in a query string format.
- * @param {string} key
- * @param {string} value
- */
- export const appendURLParams = (key, value) => {
- const searchParams = new URLSearchParams(window.location.search).set(key, value);
- return searchParams.toString();
- };
- // example
- console.log(appendURLParams("name", "youssef")) // name=youssef
- /**
- * Get param name from URL.
- * @param {string} name
- */
- export const getURLParams = (name) => new URLSearchParams(window.location.search).get(name);
- // Example
- console.log(getURLParams(id)) // 5
getInnerHTML()
每当服务器返回一串HTML元素时,我都会使用它。
- /**
- * 获取HTML字符串的内部Text
- * @param {string} str A string of HTML
- */
- export const getInnerHTML = (str) => str.replace(/(<([^>]+)>)/gi, "");
scrollToHide()
上滚动以显示HTML元素,向下滚动以将其隐藏。
- /**
- * 下滚动时隐藏HTML元素。
- * @param {string} 元素的 id
- * @param {string} distance in px ex: "100px"
- */
- export const scrollToHide = (id, distance) => {
- let prevScrollpos = window.pageYOffset;
- window.onscroll = () => {
- const currentScrollPos = window.pageYOffset;
- if (prevScrollpos > currentScrollPos) {
- document.getElementById(id).style.transform = `translateY(${distance})`;
- } else {
- document.getElementById(id).style.transform = `translateY(-${distance})`;
- }
- prevScrollpos = currentScrollPos;
- };
- };
humanFileSize ()
传入字节为单位的文件,返回我们日常所熟悉的单位。
- /**
- * Converting Bytes to Readable Human File Sizes.
- * @param {number} bytes Bytes in Number
- */
- export const humanFileSize = (bytes) => {
- let BYTES = bytes;
- const thresh = 1024;
- if (Math.abs(BYTES) < thresh) {
- return `${BYTES} B`;
- }
- const units = ["kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"];
- let u = -1;
- const r = 10 ** 1;
- do {
- BYTES /= thresh;
- u += 1;
- } while (Math.round(Math.abs(BYTES) * r) / r >= thresh && u < units.length - 1);
- return `${BYTES.toFixed(1)} ${units[u]}`;
- };
- // Example
- console.log(humanFileSize(456465465)); // 456.5 MB
getTimes()
你是否有一个DDL,它每n分钟显示一天的时间?用这个函数。
- /**
- * Getting an Array of Times + "AM" or "PM".
- * @param {number} minutesInterval
- * @param {number} startTime
- */
- export const getTimes = (minutesInterval = 15, startTime = 60) => {
- const times = []; // time array
- const x = minutesInterval; // minutes interval
- let tt = startTime; // start time
- const ap = ["AM", "PM"]; // AM-PM
- // loop to increment the time and push results in array
- for (let i = 0; tt < 24 * 60; i += 1) {
- const hh = Math.floor(tt / 60); // getting hours of day in 0-24 format
- const mm = tt % 60; // getting minutes of the hour in 0-55 format
- times[i] = `${`${hh === 12 ? 12 : hh % 12}`.slice(-2)}:${`0${mm}`.slice(-2)} ${
- ap[Math.floor(hh / 12)]
- }`; // pushing data in array in [00:00 - 12:00 AM/PM format]
- tt += x;
- }
- return times;
- };
- // Example
- console.log(getTimes());
- /* [
- "1:00 AM",
- "1:15 AM",
- "1:30 AM",
- "1:45 AM",
- "2:00 AM",
- "2:15 AM",
- "2:30 AM",
- // ....
- ]
- */
setLocalItem() & getLocalItem()
让 LocalStorage 具有过期时间。
- /**
- * Caching values with expiry date to the LocalHost.
- * @param {string} key Local Storage Key
- * @param {any} value Local Storage Value
- * @param {number} ttl Time to live (Expiry Date in MS)
- */
- export const setLocalItem = (key, value, ttl = duration.month) => {
- const now = new Date();
- // `item` is an object which contains the original value
- // as well as the time when it's supposed to expire
- const item = {
- value,
- expiry: now.getTime() + ttl,
- };
- localStorage.setItem(key, JSON.stringify(item));
- };
- /**
- * Getting values with expiry date from LocalHost that stored with `setLocalItem`.
- * @param {string} key Local Storage Key
- */
- export const getLocalItem = (key) => {
- const itemStr = localStorage.getItem(key);
- // if the item doesn't exist, return null
- if (!itemStr) {
- return null;
- }
- const item = JSON.parse(itemStr);
- const now = new Date();
- // compare the expiry time of the item with the current time
- if (now.getTime() > item.expiry) {
- // If the item is expired, delete the item from storage
- // and return null
- localStorage.removeItem(key);
- return null;
- }
- return item.value;
- };
formatNumber()
- /**
- * Format numbers with separators.
- * @param {number} num
- */
- export const formatNumber = (num) => num.toLocaleString();
- // Example
- console.log(formatNumber(78899985)); // 78,899,985
我们还可以添加其他选项来获取其他数字格式,如货币、距离、权重等。
- export const toEGPCurrency = (num) =>
- num.toLocaleString("ar-EG", { style: "currency", currency: "EGP" });
- export const toUSDCurrency = (num) =>
- num.toLocaleString("en-US", { style: "currency", currency: "USD" });
- console.log(toUSDCurrency(78899985)); // $78,899,985.00
- console.log(toEGPCurrency(78899985)); // ٧٨٬٨٩٩٬٩٨٥٫٠٠ ج.م.
toFormData()
每当我需要向服务器发送文件时,我就使用这个函数。
- /**
- * Convert Objects to Form Data Format.
- * @param {object} obj
- */
- export const toFormData = (obj) => {
- const formBody = new FormData();
- Object.keys(obj).forEach((key) => {
- formBody.append(key, obj[key])
- })
- return formBody;
- }
getScreenWidth()
获取一个表示屏幕宽度的字符串。
- /**
- * Detect screen width and returns a string representing the width of the screen.
- */
- export const getScreenWidth = () => {
- const screenWidth = window.screen.width;
- if (screenWidth <= 425) return "mobile";
- if (screenWidth <= 768) return "tablet";
- if (screenWidth <= 1024) return "laptopSm";
- if (screenWidth <= 1440) return "laptopLg";
- if (screenWidth <= 2560) return "HD";
- return screenWidth;
- };
检查数组中的每个元素是否存在于另一个数组中。
- export const containsAll = (baseArr, arr) => {
- let all = false;
- for (let i = 0; i < arr.length; i += 1) {
- if (baseArr.includes(arr[i])) {
- all = true;
- } else {
- all = false;
- return all;
- }
- }
- return all;
- };
你还有使用其他有用的函数吗?在评论里分享一下怎么样?
完~,我是小智,我要去刷碗去了。
作者:YoussefZidan 译者:前端小智 来源:dev原文:https://dev.to/youssefzidan/javascript-functions-that-will-make-your-life-much-easier-1imh
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