[回答] 有哪些短小却令人惊叹的 JavaScript 代码？

一些短小但令人惊叹的 JavaScript 代码：

• 翻转字符串：

const reverseString = str => str.split("").reverse().join("");

判断回文字符串：const isPalindrome = str => str === str.split("").reverse().join(""); 查找数组中的最大值：const arr = [1, 2, 3, 4, 5]; const maxNum = Math.max(...arr); 数组去重：const arr = [1, 1, 2, 2, 3, 4, 4, 5]; const uniqueArr = [...new Set(arr)]; 计算数组中的总和：const arr = [1, 2, 3, 4, 5]; const sum = arr.reduce((total, num) => total + num); 交换两个变量的值：let a = 1, b = 2; [b, a] = [a, b]; 筛选出符合条件的数组元素：const arr = [1, 2, 3, 4, 5]; const filteredArr = arr.filter(num => num % 2 === 0); 数组扁平化：const arr = [1, [2, [3, [4]]]]; const flattenedArr = arr.flat(Infinity); 数组乱序：const arr = [1, 2, 3, 4, 5]; const shuffledArr = arr.sort(() => Math.random() - 0.5); 防抖：const debounce = (func, delay) => { let timer; return (...args) => { clearTimeout(timer); timer = setTimeout(() => func(...args), delay); }; }; 节流：const throttle = (func, limit) => { let inThrottle; return (...args) => { if (!inThrottle) { inThrottle = true; func(...args); setTimeout(() => inThrottle = false, limit); } }; }; 判断变量是否为数组：const arr = [1, 2, 3]; const isArray = Array.isArray(arr); 对象属性解构：const obj = { x: 1, y: 2 }; const { x, y } = obj; 深拷贝对象：const deepCopy = obj => JSON.parse(JSON.stringify(obj));

• 求数组中的平均值：

const arr = [1, 2, 3, 4, 5]; const average = arr.reduce((total, num) => total + num) / arr.length; 检查字符串是否以指定的字符串开头：const str = "Hello, world!"; const startsWithHello = str.startsWith("Hello"); 检查字符串是否以指定的字符串结尾：const str = "Hello, world!"; const endsWithWorld = str.endsWith("world!"); 快速判断一个数字是否是偶数：const isEven = num => (num & 1) === 0; 将数字格式化为货币：const amount = 12345.67; const formattedAmount = amount.toLocaleString("en-US", { style: "currency", currency: "USD" }); 创建指定长度和默认值的数组：const length = 5; const defaultValue = 0; const arr = Array.from({ length }, () => defaultValue); 使用 Promise.all 并行处理多个异步操作：const urls = ["https://example.com/api/1", "https://example.com/api/2", "https://example.com/api/3"]; const requests = urls.map(url => fetch(url)); const responses = await Promise.all(requests); const data = await Promise.all(responses.map(response => response.json())); 这些代码同样具有高效和易用性，但在实际项目中需要注意其上下文和使用场景，以确保其正确性和有效性。