【前端面试】同窗,你会手写代码吗?

若是您发现错误,请必定要告诉我,拯救一个辣鸡(但很帅)的少年就靠您了!javascript

CSS 部分

两栏布局

要求:垂直两栏,左边固定右边自适应。css

查看代码
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style> .outer { height: 100px; margin-bottom: 10px; } .left { background: tomato; height: 100px; } .right { background: gold; height: 100px; } /* 浮动 */ .outer1 .left { width: 200px; float: left; } .outer1 .right { width: auto; margin-left: 200px; } /* flex */ .outer2 { display: flex; } .outer2 .left { flex-grow: 0; flex-shrink: 0; flex-basis: 200px; } .outer2 .right { flex: auto; /* 1 1 auto */ } /* position */ .outer3 { position: relative; } .outer3 .left { position: absolute; width: 200px; } .outer3 .right { margin-left: 200px; } /* position again */ .outer4 { position: relative; } .outer4 .left { width: 200px; } .outer4 .right { position: absolute; top: 0; left: 200px; right: 0; } </style>
</head>
<!-- 左右两栏,左边固定,右边自适应 -->
<body>
    <div class="outer outer1">
        <div class="left">1-left</div>
        <div class="right">1-right</div>
    </div>
    <div class="outer outer2">
        <div class="left">2-left</div>
        <div class="right">2-right</div>
    </div>
    <div class="outer outer3">
        <div class="left">3-left</div>
        <div class="right">3-right</div>
    </div>
    <div class="outer outer4">
        <div class="left">4-left</div>
        <div class="right">4-right</div>
    </div>
</body>
</html>
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三栏布局

要求:垂直三栏布局,左右两栏宽度固定,中间自适应html

查看代码
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style> .outer, .left, .middle, .right { height: 100px; margin-bottom: 5px; } .left { background: tomato; } .middle { background: lightgreen; } .right { background: gold; } /* 左右分别设置绝对定位 中间设置外边距 */ .outer1 { position: relative; } .outer1 .left { position: absolute; width: 100px; } .outer1 .middle { margin: 0 200px 0 100px; } .outer1 .right { position: absolute; width: 200px; top: 0; right: 0; } /* flex 布局 */ .outer2 { display: flex; } .outer2 .left { flex: 0 0 100px; } .outer2 .middle { flex: auto; } .outer2 .right { flex: 0 0 200px; } /* 浮动布局 可是 html 中 middle要放到最后 */ .outer3 .left { float: left; width: 100px; } .outer3 .right { float: right; width: 200px; } .outer3 .middle { margin: 0 200px 0 100px; } </style>
</head>
<!-- 三栏布局 左右固定 中间自适应 -->
<body>
    <div class="outer outer1">
        <div class="left">1-left</div>
        <div class="middle">1-middle</div>
        <div class="right">1-right</div>
    </div>
    <div class="outer outer2">
        <div class="left">2-left</div>
        <div class="middle">2-middle</div>
        <div class="right">2-right</div>
    </div>
    <div class="outer outer3">
        <div class="left">3-left</div>
        <div class="right">3-right</div>
        <div class="middle">3-middle</div>
    </div>
</body>
</html>
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圣杯布局 和 双飞翼布局

和三栏布局要求相同,不过中间列要写在前面保证优先渲染。前端

查看代码
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style> .outer, .left, .middle, .right { height: 100px; margin-bottom: 5px; } .left { background: tomato; } .middle { background: lightgreen; } .right { background: gold; } /* 圣杯布局 经过浮动和负边距实现 */ .outer1 { padding: 0 200px 0 100px; } .outer1 .middle { width: 100%; float: left; } .outer1 .left { width: 100px; float: left; margin-left: -100%; position: relative; left: -100px; } .outer1 .right { width: 200px; float: left; margin-left: -200px; position: relative; left: 200px; } /* 双飞翼布局 */ .outer2 .middle-wrapper { width: 100%; float: left; } .outer2 .middle { margin: 0 200px 0 100px; } .outer2 .left { width: 100px; float: left; margin-left: -100%; } .outer2 .right { width: 200px; float: left; margin-left: -200px; } </style>
</head>
<!-- 三栏布局 左右固定 中间自适应 -->
<body>
    <!-- 圣杯布局 middle 最早 -->
    <div class="outer outer1">
        <div class="middle">圣杯-middle</div>
        <div class="left">圣杯-left</div>
        <div class="right">圣杯-right</div>
    </div>
    <!-- 双飞翼布局 middle 最早 多一层 div -->
    <div class="outer outer2">
        <div class="middle-wrapper">
            <div class="middle">双飞翼布局-middle</div>
        </div>
        <div class="left">双飞翼布局-left</div>
        <div class="right">双飞翼布局-right</div>
    </div>
</body>
</html>
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三角形

实现一个三角形java

常见题目,经过 border 实现es6

查看代码
<!DOCTYPE html>
<html>
<head>
  <title>三角形</title>
  <style type="text/css"> .box1, .box2, .box3, .box4 { height: 0px; width: 0px; float: left; border-style: solid; margin: 10px; } .box1 { /* 等腰直角 */ border-width: 100px; border-color: tomato transparent transparent transparent; } .box2 { /* 等边 */ border-width: 100px 173px; border-color: transparent tomato transparent transparent; } .box3 { /* 等腰 */ border-width: 100px 80px; border-color: transparent transparent tomato transparent; } .box4 { /* 其余 */ border-width: 100px 90px 80px 70px; border-color: transparent transparent transparent tomato; } </style>
</head>
<body>
  <div class="box1"></div>
  <div class="box2"></div>
  <div class="box3"></div>
  <div class="box4"></div>
</body>
</html>
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正方形

使用 css 实现一个宽高自适应的正方形web

查看代码
<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style> /* 都是像对于屏幕宽度的比例 */ .square1 { width: 10%; height: 10vw; background: red; } /* margin/padding 百分比是相对父元素 width 的 */ .square2 { width: 20%; height: 0; padding-top: 20%; background: orange; } /* 经过子元素 margin */ .square3 { width: 30%; overflow: hidden; /* 触发 BFC */ background: yellow; } .square3::after { content: ''; display: block; margin-top: 100%; /* 高度相对于 square3 的 width */ } </style>
	</head>
	<!-- 画一个正方形 -->
	<body>
		<div class="square1"></div>
		<div class="square2"></div>
		<div class="square3"></div>
	</body>
</html>
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扇形

实现一个 1/4 圆、任意弧度的扇形ajax

有多种实现方法,这里选几种简单方法(我看得懂的)实现。json

查看代码
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style> /* 经过 border 和 border-radius 实现 1/4 圆 */ .sector1 { height: 0; width: 0; border: 100px solid; border-radius: 50%; border-color: turquoise tomato tan thistle; } /* 相似三角形的作法加上父元素 overflow: hidden; 也能够实现任意弧度圆 */ .sector2 { height: 100px; width: 200px; border-radius: 100px 100px 0 0; overflow: hidden; } .sector2::after { content: ''; display: block; height: 0; width: 0; border-style: solid; border-width: 100px 58px 0; border-color: tomato transparent; transform: translate(42px,0); } /* 经过子元素 rotateZ 和父元素 overflow: hidden 实现任意弧度扇形(此处是60°) */ .sector3 { height: 100px; width: 100px; border-top-right-radius: 100px; overflow: hidden; /* background: gold; */ } .sector3::after { content: ''; display: block; height: 100px; width: 100px; background: tomato; transform: rotateZ(-30deg); transform-origin: left bottom; } /* 经过 skewY 实现一个60°的扇形 */ .sector4 { height: 100px; width: 100px; border-top-right-radius: 100px; overflow: hidden; } .sector4::after { content: ''; display: block; height: 100px; width: 100px; background: tomato; transform: skewY(-30deg); transform-origin: left bottom; } /* 经过渐变设置60°扇形 */ .sector5 { height: 200px; width: 200px; background: tomato; border-radius: 50%; background-image: linear-gradient(150deg, transparent 50%, #fff 50%), linear-gradient(90deg, #fff 50%, transparent 50%); } </style>
</head>
<body>
    <div style="display: flex; justify-content: space-around;">
        <div class="sector1"></div>
        <div class="sector2"></div>
        <div class="sector3"></div>
        <div class="sector4"></div>
        <div class="sector5"></div>
    </div>
</body>
</html>
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水平垂直居中

实现子元素的水平垂直居中跨域

查看代码
<!DOCTYPE html>
<html>
<head>
  <title>水平垂直居中</title>
  <style type="text/css"> .outer { height: 200px; width: 200px; background: tomato; margin: 10px; float: left; position: relative; } .inner { height: 100px; width: 100px; background: black; } /* * 经过 position 和 margin 居中 * 缺点:须要知道 inner 的长宽 */ .inner1 { position: absolute; top: 50%; left: 50%; margin-top: -50px; margin-left: -50px; } /* * 经过 position 和 margin 居中 (2 */ .inner2 { position: absolute; top: 0; right: 0; bottom: 0; left: 0; margin: auto; } /* * 经过 flex 进行居中 */ .outer3 { display: flex; justify-content: center; align-items: center; } /** * 经过 position 和 transform 居中 */ .inner4 { top: 50%; left: 50%; transform: translate(-50%,-50%); position: absolute; } </style>
</head>
<body>
  <div class="outer outer1">
    <div class="inner inner1"></div>
  </div>
  <div class="outer outer2">
    <div class="inner inner2"></div>
  </div>
  <div class="outer outer3">
    <div class="inner inner3"></div>
  </div>
  <div class="outer outer4">
    <div class="inner inner4"></div>
  </div>
</body>
</html>
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清除浮动

要求:清除浮动

能够经过 clear:both 或 BFC 实现

查看代码
<!DOCTYPE html>
<html>
<head>
  <title>清除浮动</title>
  <style type="text/css"> .outer { width: 200px; background: tomato; margin: 10px; position: relative; } .inner { height: 100px; width: 100px; background: pink; margin: 10px; float: left; } /* 伪元素 */ .outer1::after { content: ''; display: block; clear: both; } /* 建立 BFC */ .outer2 { overflow: hidden; } </style>
</head>
<body>
  <div class="outer outer1">
    <div class="inner"></div>
  </div>
  <div class="outer outer2">
    <div class="inner"></div>
  </div>
</body>
</html>
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弹出框

使用 CSS 写一个弹出框效果

查看代码
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style> .bg { height: 666px; width: 100%; font-size: 60px; text-align: center; } .dialog { z-index: 999; position: fixed; top: 0; right: 0; bottom: 0; left: 0; background: rgba(0, 0, 0, 0.5); } .dialog .content { min-height: 300px; width: 600px; background: #fff; border-radius: 5px; border: 1px solid #ebeef5; box-shadow: 0 2px 12px 0 rgba(0,0,0,.1); position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); } </style>
</head>
<body>
    <div class="bg">
        页面内容
    </div>
    <div class="dialog">
        <div class="content">
            弹出框
        </div>
    </div>
</body>
</html>
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导航栏

要求:一个 div 内部放不少水平 div ,并能够横向滚动。

查看代码
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=div, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style> body,html { margin: 0; padding: 0; } /* flex 实现 */ /* .nav { display: flex; height: 30px; border: 1px solid #000; padding: 3px; overflow-x: auto; } .nav::-webkit-scrollbar { display: none; } .item { flex: 0 0 200px; height: 30px; margin-right: 5px; background: gray; } */ /* inline-block 和 white-space: nowrap; 实现 */ .nav { height: 30px; padding: 3px; border: 1px solid #000; overflow-x: auto; white-space: nowrap; } .nav::-webkit-scrollbar { display: none; } .item { display: inline-block; width: 200px; height: 30px; margin-right: 5px; background: gray; } </style>
</head>
<!-- 水平滚动导航栏 -->
<body>
    <div class="nav">
        <div class="item">item1</div>
        <div class="item">item2</div>
        <div class="item">item3</div>
        <div class="item">item4</div>
        <div class="item">item5</div>
        <div class="item">item6</div>
        <div class="item">item7</div>
        <div class="item">item8</div>
        <div class="item">item9</div>
    </div>
</body>
</html>
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CSS 部分完,总结,Flex 无敌。

JavaScript 部分

手写 bind、call 和 apply

Function.prototype.bind = function(context, ...bindArgs) {
  // func 为调用 bind 的原函数
  const func = this;
  context = context || window;
  
  if (typeof func !== 'function') {
    throw new TypeError('Bind must be called on a function');
  }
  // bind 返回一个绑定 this 的函数
  return function(...callArgs) {
    let args = bindArgs.concat(callArgs);
    if (this instanceof func) {
      // 意味着是经过 new 调用的 而 new 的优先级高于 bind
      return new func(...args);
    }
    return func.call(context, ...args);
  }
}

// 经过隐式绑定实现
Function.prototype.call = function(context, ...args) {
  context = context || window;
  context.func = this;

  if (typeof context.func !== 'function') {
    throw new TypeError('call must be called on a function');
  }

  let res = context.func(...args);
  delete context.func;
  return res;
}

Function.prototype.apply = function(context, args) {
  context = context || window;
  context.func = this;

  if (typeof context.func !== 'function') {
    throw new TypeError('apply must be called on a function');
  }

  let res = context.func(...args);
  delete context.func;
  return res;
}
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实现一个继承

// 参考 You Dont Know JavaScript 上卷
// 基类
function Base() {
}
// 派生类
function Derived() {
    Base.call(this);
}
// 将派生类的原型的原型链挂在基类的原型上
Object.setPrototypeOf(Derived.prototype, Base.prototype);
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实现一个 new

// 手动实现一个 new 关键字的功能的函数 _new(fun, args) --> new fun(args)
function _new(fun, ...args) {
    if (typeof fun !== 'function') {
        return new Error('参数必须是一个函数');
    }
    let obj = Object.create(fun.prototype);
    let res = fun.call(obj, ...args);
    if (res !== null && (typeof res === 'object' || typeof res === 'function')) {
        return res;
    }
    return obj;
}
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实现一个 instanceof

// a instanceof b
function _instanceof(a, b) {
    while (a) {
        if (a.__proto__ === b.prototype) return true;
        a = a.__proto__;
    }
    return false;
}
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手写 jsonp 的实现

// foo 函数将会被调用 传入后台返回的数据
function foo(data) {
    console.log('经过jsonp获取后台数据:', data);
    document.getElementById('data').innerHTML = data;
}
/** * 经过手动建立一个 script 标签发送一个 get 请求 * 并利用浏览器对 <script> 不进行跨域限制的特性绕过跨域问题 */
(function jsonp() {
    let head = document.getElementsByTagName('head')[0]; // 获取head元素 把js放里面
    let js = document.createElement('script');
    js.src = 'http://domain:port/testJSONP?a=1&b=2&callback=foo'; // 设置请求地址
    head.appendChild(js); // 这一步会发送请求
})();

// 后台代码
// 由于是经过 script 标签调用的 后台返回的至关于一个 js 文件
// 根据前端传入的 callback 的函数名直接调用该函数
// 返回的是 'foo(3)'
function testJSONP(callback, a, b) {
  return `${callback}(${a + b})`;
}
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ajax 的实现

感受这个有点无聊了……

查看代码
// Asynchronous Javascript And XML
function ajax(options) {
  // 选项
  var method = options.method || 'GET',
      params = options.params,
      data = options.data,
      url = options.url + (params ? '?' + Object.keys(params).map(key => key + '=' + params[key]).join('&') : ''),
      async = options.async === false ? false : true,
      success = options.success,
      headers = options.headers;

  var request;
  if (window.XMLHttpRequest) {
    request = new XMLHttpRequest();
  } else {
    request = new ActiveXObject('Microsoft.XMLHTTP');
  }

  request.onreadystatechange = function() {
    /** readyState: 0: 请求未初始化 1: 服务器链接已创建 2: 请求已接收 3: 请求处理中 4: 请求已完成,且响应已就绪 status: HTTP 状态码 **/
    if (request.readyState === 4 && request.status === 200) {
      success && success(request.responseText);
    }
  }

  request.open(method, url, async);
  if (headers) {
    Object.keys(headers).forEach(key => request.setRequestHeader(key, headers[key]));
  }
  method === 'GET' ? request.send() : request.send(data);
}
// e.g.
ajax({
  method: 'GET',
  url: '...',
  success: function(res) {
    console.log('success', res);
  },
  async: true,
  params: {
    p: 'test',
    t: 666
  },
  headers: {
    'Content-Type': 'application/json'
  }
})
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reduce 的实现

function reduce(arr, callback, initial) {
    let i = 0;
    let acc = initial === undefined ? arr[i++] : initial;
    for (; i < arr.length; i++) {
        acc = callback(acc, arr[i], i, arr);
    }
    return acc;
}
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实现 generator 的自动执行器

要求是 yield 后面只能是 PromiseThunk 函数,详见 es6.ruanyifeng.com/#docs/gener…

function run(gen) {
  let g = gen();

  function next(data) {
    let result = g.next(data);
    if (result.done) return result.value;
    if (result.value instanceof Promise) {
      result.value.then(data => next(data));
    } else {
      result.value(next);
    }
  }

  return next();
}

// ======== e.g. ==========

function func(data, cb) {
  console.log(data);
  cb();
}

function *gen() {
  let a = yield Promise.resolve(1);
  console.log(a);
  let b = yield Promise.resolve(2);
  console.log(b);
  yield func.bind(null, a + b);
}
run(gen);
/** output: 1 2 3 **/
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节流

老生常谈了,感受不必写太复杂

/** * 节流函数 限制函数在指定时间段只能被调用一次 * 用法 好比防止用户连续执行一个耗时操做 对操做按钮点击函数进行节流处理 */
function throttle(func, wait) {
  let timer = null;
  return function(...args) {
    if (!timer) {
      func(...args);
      timer = setTimeout(() => {
        timer = null;
      }, wait);
    }
  }
}
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防抖

/** * 函数调用后不会被当即执行 以后连续 wait 时间段没有调用才会执行 * 用法 如处理用户输入 */
function debounce(func, wait) {
  let timer = null;
  
  return function(...args) {
    if (timer) clearTimeout(timer); // 若是在定时器未执行期间又被调用 该定时器将被清除 并从新等待 wait 秒
    timer = setTimeout(() => {
      func(...args);
    }, wait);
  }
}
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手写 Promise

简单实现,基本功能都有了。

const PENDING = 1;
const FULFILLED = 2;
const REJECTED = 3;

function MyPromise(executor) {
    let self = this;
    this.resolveQueue = [];
    this.rejectQueue = [];
    this.state = PENDING;
    this.val = undefined;
    function resolve(val) {
        if (self.state === PENDING) {
            setTimeout(() => {
                self.state = FULFILLED;
                self.val = val;
                self.resolveQueue.forEach(cb => cb(val));
            });
        }
    }
    function reject(err) {
        if (self.state === PENDING) {
            setTimeout(() => {
                self.state = REJECTED;
                self.val = err;
                self.rejectQueue.forEach(cb => cb(err));
            });
        }
    }
    try {
        // 回调是异步执行 函数是同步执行
        executor(resolve, reject);
    } catch(err) {
        reject(err);
    }
}

MyPromise.prototype.then = function(onResolve, onReject) {
    let self = this;
    // 不传值的话默认是一个返回原值的函数
    onResolve = typeof onResolve === 'function' ? onResolve : (v => v); 
    onReject = typeof onReject === 'function' ? onReject : (e => { throw e });
    if (self.state === FULFILLED) {
        return new MyPromise(function(resolve, reject) {
            setTimeout(() => {
                try {
                    let x = onResolve(self.val);
                    if (x instanceof MyPromise) {
                        x.then(resolve);
                    } else {
                        resolve(x);
                    }
                } catch(e) {
                    reject(e);
                }
            });
        });
    }

    if (self.state === REJECTED) {
        return new MyPromise(function(resolve, reject) {
            setTimeout(() => {
                try {
                    let x = onReject(self.val);
                    if (x instanceof MyPromise) {
                        x.then(resolve);
                    } else {
                        resolve(x);
                    }
                } catch(e) {
                    reject(e);
                }
            });
        });
    }
    
    if (self.state === PENDING) {
        return new MyPromise(function(resolve, reject) {
            self.resolveQueue.push((val) => {
                try {
                    let x = onResolve(val);
                    if (x instanceof MyPromise) {
                        x.then(resolve);
                    } else {
                        resolve(x);
                    }
                } catch(e) {
                    reject(e);
                }
            });
            self.rejectQueue.push((val) => {
                try {
                    let x = onReject(val);
                    if (x instanceof MyPromise) {
                        x.then(resolve);
                    } else {
                        resolve(x);
                    }
                } catch(e) {
                    reject(e);
                }
            });
        });
    }
}

MyPromise.prototype.catch = function(onReject) {
    return this.then(null, onReject);
}

MyPromise.all = function(promises) {
    return new MyPromise(function(resolve, reject) {
        let cnt = 0;
        let result = [];
        for (let i = 0; i < promises.length; i++) {
            promises[i].then(res => {
                result[i] = res;
                if (++cnt === promises.length) resolve(result);
            }, err => {
                reject(err);
            })
        }
    });
}

MyPromise.race = function(promises) {
    return new MyPromise(function(resolve, reject) {
        for (let i = 0; i < promises.length; i++) {
            promises[i].then(resolve, reject);
        }
    });
}

MyPromise.resolve = function(val) {
    return new MyPromise(function(resolve, reject) {
        resolve(val);
    });
}

MyPromise.reject = function(err) {
    return new MyPromise(function(resolve, reject) {
        reject(err);
    })
}
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实现一个路由 - Hash

实现原理就是监听 url 的哈希值变化了

<!DOCTYPE html>
<html>
<head>
  <title>hash 路由</title>
</head>
<body>
  <header>
    <a href="#home">首页</a>
    <a href="#center">我的中心页</a>
    <a href="#help">帮助页</a>
  </header>
  <section id="content"></section>
  <script> window.addEventListener('hashchange', (e) => { let content = document.getElementById('content'); content.innerText = location.hash; }) </script>
</body>
</html>
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路由实现 - history

<!DOCTYPE html>
<html>
<head>
  <title>history 路由</title>
</head>
<body>
  <header>
    <a onclick="changeRoute(this)" data-path="home">首页</a>
    <a onclick="changeRoute(this)" data-path="center">我的中心页</a>
    <a onclick="changeRoute(this)" data-path="help">帮助页</a>
  </header>
  <section id="content"></section>
  <script> function changeRoute(route) { let path = route.dataset.path; /** * window.history.pushState(state, title, url) * state:一个与添加的记录相关联的状态对象,主要用于popstate事件。该事件触发时,该对象会传入回调函数。 * 也就是说,浏览器会将这个对象序列化之后保留在本地,从新载入这个页面的时候,能够拿到这个对象。 * 若是不须要这个对象,此处能够填 null。 * title:新页面的标题。可是,如今全部浏览器都忽视这个参数,因此这里能够填空字符串。 * url:新的网址,必须与当前页面处在同一个域。浏览器的地址栏将显示这个网址。 */ changePage(path); history.pushState({ content: path }, null, path); } /** * 调用 history.pushState() 或者 history.replaceState() 不会触发 popstate 事件。 * 点击后退、前进按钮、或者在 js 中调用 history.back()、history.forward()、history.go() 方法会触发 */ window.addEventListener('popstate', (e) => { let content = e.state && e.state.content; changePage(content); }); function changePage(pageContent) { let content = document.getElementById('content'); content.innerText = pageContent; } </script>
</body>
</html>
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还有一些稍复杂的能够写,有时间再补。

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