JavaScript，这种强大的语言几乎涉及到编程各个方面：前端、后端、web应用程序、桌面应用程序、移动应用程序等等。千锋长沙Web前端培训班分享整理了18个常用的JavaScript片段，在日常开发工作中，它们为我大大节省了时间。

1. maxItemOfArray

获取数组中的最大数字

const maxItemOfArray = (arr) => arr.sort((a, b) => b - a)[0];let maxItem = maxItemOfArray([3, 5, 12, 5]);

2. areAllEqual

检查数组的所有项是否相等

const areAllEqual = array => array.every(item => item === array[0]);

let check1 = areAllEqual([3, 5, 2]); // false

let check2 = allEqual([3, 3, 3]); // true

3. averageOf

求给定数字的平均值

const averageOf = (…numbers) => numbers.reduce((a, b) => a + b, 0) / numbers.length;

let average = averageOf(5, 2, 4, 7); // 4.5

4. reverseString

反转一个字符串

const reverseString = str => […str].reverse().join(‘’);

let a = reverseString(‘Have a nice day!’); // !yad ecin a evaH

5. sumOf

求给定数字的和

const sumOf = (…numbers) => numbers.reduce((a, b) => a + b, 0);

let sum = sumOf(5, -3, 2, 1); // 5

6. findAndReplace

在字符串中查找给定的单词，并替换为另一个单词

const findAndReplace = (string, wordToFind, wordToReplace) => string.split(wordToFind).join(wordToReplace);

let result = findAndReplace(‘I like banana’, ‘banana’, ‘apple’); // I like apple

7. RGBToHex

将RGB模式下的颜色转换为十六进制

const RGBToHex = (r, g, b) => ((r << 16) + (g << 8) + b).toString(16).padStart(6, ‘0’);

let hex = RGBToHex(255, 255, 255); // ffffff

8. shuffle

音乐播放器如何随机播放播放项目？

const shuffle = ([…array]) => {

let m = array.length;

while (m) {

const i = Math.floor(Math.random() * m — );

[array[m], array[i]] = [array[i], array[m]];

}

return array;

};

shuffle([5, 4, 3, 6, 20]);

9. removeFalseValues

从数组中删除false值，包括false，undefined，NaN，empty

const removeFalseValues = arr => arr.filter(item => item);

let arr = removeFalseValues([3, 4, false, ‘’, 5, true, undefined, NaN, ‘’]); // [3, 4, 5, true]

10. removeDuplicatedValues

从数组中删除重复的项

const removeDuplicatedValues = array => […new Set(array)];

let arr = removeDuplicatedValues([5, 3, 2, 5, 6, 1, 1, 6]); // [5, 3, 2, 6, 1]

11. getTimeFromDate

以日期对象的字符串形式返回时间

const getTimeFromDate = date => date.toTimeString().slice(0, 8);

let time = getTimeFromDate(new Date()); // 09:46:08

12. capitalizeAllWords

将字符串中所有单词的首个字母大写

const capitalizeAllWords = str => str.replace(/\b[a-z]/g, char => char.toUpperCase());

let str = capitalizeAllWords(‘i love reading book’); // I Love Reading Book

13. getDayDiff

返回两个日期之间以天为单位的差值

const getDayDiff = (date1, date2) => ((date2 - date1) / (1000 * 3600 * 24));let diff = getDayDiff(new Date('2020-04-01'), new Date('2020-08-15')); // 136

14. radianToDegree

把弧度转换成角度

const radianToDegree = radian => (radian * 180.0) / Math.PI;let degree = radianToDegree(2.3); // 131.78

15. isValidJSON

检查给定字符串是否是有效的JSON

const isValidJSON = string => { try { JSON.parse(string); return true; } catch (error) { return false; }};let check1 = isValidJSON(‘{“title”: “javascript”, “price”: 14}’); // truelet check2 = isValidJSON(‘{“title”: “javascript”, “price”: 14, sub title}’); // false

16. toWords

将给定的字符串转换为单词数组

const toWords = (string, pattern = /[^a-zA-Z-]+/) => string.split(pattern).filter(item => item);

let words = toWords(‘I want to be come a great programmer’); // [“I”, “want”,“to”, “be”, “come”, “a”, “great”, “programmer”]

17. scrollToTop

位于长页面的底部，并且想快速向上滚动至顶部

const scrollToTop = () => { const t = document.documentElement.scrollTop || document.body.scrollTop; if (t > 0) { window.requestAnimationFrame(scrollToTop); window.scrollTo(0, t — t / 8); }};

18. isValidNumber

验证数字是否有效

const isValidNumber = n => !isNaN(parseFloat(n)) && isFinite(n) && Number(n) =

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