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20个叹为观止的JavaScript一行代码

20个叹为观止的JavaScript一行代码

作者: 我爱娃哈哈76 | 来源:发表于2023-03-08 09:56 被阅读0次

    1、获取浏览器cookie值

    const cookie = name => `; ${document.cookie}`.split(`; ${name}=`).pop().split(';').shift();
    
    cookie('_ga');
    // Result: "GA1.2.1929736587.1601974046"
    
    
    

    2、将RGB转换为16进制

    const rgbToHex = (r, g, b) =>
    "#" + ((1 << 24) + (r << 16) + (g << 8) + b).toString(16).slice(1);
    
    rgbToHex(0, 51, 255);
    // Result: #0033ff`
    
    
    

    3、复制到剪切板(使用 navigator.clipboard.writeText 轻松将任何文本复制到剪贴板上)

    const copyToClipboard = (text) => navigator.clipboard.writeText(text);
    
    copyToClipboard("Hello World");
    
    
    

    4、检查日期是否有效

    const isDateValid = (...val) => !Number.isNaN(new Date(...val).valueOf());
    
    isDateValid("December 17, 1995 03:24:00");
    // Result: true
    
    
    

    5、找出一年中的某一天(即给出一个日期,程序给出属于本年的第多少天)

    const dayOfYear = (date) =>
    Math.floor((date - new Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);
    
    dayOfYear(new Date());
    // Result: 272
    
    

    6、将字符串首字母大写

    const capitalize = str => str.charAt(0).toUpperCase() + str.slice(1)
    
    capitalize("follow for more")
    // Result: Follow for more
    
    
    

    7、计算两个日期之间相差的天数

    const dayDif = (date1, date2) => Math.ceil(Math.abs(date1.getTime() - date2.getTime()) / 86400000)
    
    dayDif(new Date("2020-10-21"), new Date("2021-10-22"))
    // Result: 366
    
    
    

    8、清除所有cookie

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

    9、生成随机16进制

    const randomHex = () => `#${Math.floor(Math.random() * 0xffffff).toString(16).padEnd(6, "0")}`;
    
    console.log(randomHex());
    // Result: #92b008
    
    
    

    10、数组去重

    const removeDuplicates = (arr) => [...new Set(arr)];
    
    console.log(removeDuplicates([1, 2, 3, 3, 4, 4, 5, 5, 6]));
    // Result: [ 1, 2, 3, 4, 5, 6 ]
    
    
    

    11、从URL中获取查询参数

    const getParameters = (URL) => {
    URL = JSON.parse('{"' + decodeURI(URL.split("?")[1]).replace(/"/g, '\\"').replace(/&/g, '","').replace(/=/g, '":"') +'"}');
    return JSON.stringify(URL);
    };
    
    getParameters(window.location)
    // Result: { search : "easy", page : 3 }
    
    
    

    12、从日期中获取“时分秒”格式的时间

    const timeFromDate = date => date.toTimeString().slice(0, 8);
    
    console.log(timeFromDate(new Date(2021, 0, 10, 17, 30, 0)));
    // Result: "17:30:00"
    
    
    

    13、确认奇偶数

    //通过数据%2来判断并返回布尔类型
    const isEven = num => num % 2 === 0;
    
    console.log(isEven(2));
    // Result: True
    
    
    

    14、求平值

    const average = (...args) => args.reduce((a, b) => a + b) / args.length;
    
    average(1, 2, 3, 4);
    // Result: 2.5
    
    
    

    15、回到顶部(适用于网页右下角快捷返回功能)

    //通过将x、y设置为0来实现
    const goToTop = () => window.scrollTo(0, 0);
    
    goToTop();
    
    
    

    16、反转字符串

    const reverse = str => str.split('').reverse().join('');
    
    reverse('hello world');
    // Result: 'dlrow olleh'
    
    
    

    17、检查数组是否为空

    //通过对数组长度判断来确定是否为空
    const isNotEmpty = arr => Array.isArray(arr) && arr.length > 0;
    
    isNotEmpty([1, 2, 3]);
    // Result: true
    
    
    

    18、获取用户选定的文本

    const getSelectedText = () => window.getSelection().toString();
    
    getSelectedText();
    
    
    

    19、打乱数组

    const shuffleArray = (arr) => arr.sort(() => 0.5 - Math.random());
    
    console.log(shuffleArray([1, 2, 3, 4]));
    // Result: [ 1, 4, 3, 2 ]
    
    
    

    20、检查用户是否处于暗模式

    const isDarkMode = window.matchMedia && window.matchMedia('(prefers-color-scheme: dark)').matches
    
    console.log(isDarkMode) // Result: True or False
    
    
    

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