前端必懂的设计模式-门面模式

class Sum {
    sum(a, b) {
        return a + b;
    }
}
class Minus {
    minus(a, b) {
        return a - b;
    }
}
class Multiply {
    multiply(a, b) {
        return a * b;
    }
}
class Calculator {
    sumObj
    minusObj
    multiplyObj
    constructor() {
        this.sumObj = new Sum();
        this.minusObj = new Minus();
        this.multiplyObj = new Multiply();
    }
    sum(...args) {
        return this.sumObj.sum(...args);
    }
    minus(...args) {
        return this.minusObj.minus(...args);
    }
    multiply(...args) {
        return this.multiplyObj.multiply(...args);
    }
}
let calculator = new Calculator();
console.log(calculator.sum(1, 2));
console.log(calculator.minus(1, 2));
console.log(calculator.multiply(1, 2));
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class CPU {
    startup() { console.log('打开CPU'); }
    shutdown() { console.log('关闭CPU'); }
}
class Memory {
    startup() { console.log('打开内存'); }
    shutdown() { console.log('关闭内存'); }
}
class Disk {
    startup() { console.log('打开硬盘'); }
    shutdown() { console.log('关闭硬盘'); }
}
class Computer {
    cpu;
    memory;
    disk;
    constructor() {
        this.cpu = new CPU();
        this.memory = new Memory();
        this.disk = new Disk();
    }
    startup() {
        this.cpu.startup();
        this.memory.startup();
        this.disk.startup();
    }
    shutdown() {
        this.cpu.shutdown();
        this.memory.shutdown();
        this.disk.shutdown();
    }
}
let computer = new Computer();
computer.startup();
computer.shutdown();
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export { }
var zlib = require('zlib');
var fs = require('fs');
let path = require('path');
function open(input) {
    let ext = path.extname(input);
    switch (ext) {
        case '.gz':
            return unZip(input);
        case '.rar':
            return unRar(input);
        case '.7z':
            return un7z(input);
        default:
            break;
    }
}
function unZip(src) {
    var gunzip = zlib.createGunzip();
    var inputStream = fs.createReadStream(src);
    var outputStream = fs.createWriteStream(src.slice(0, -3));
    console.log('outputStream');

    inputStream.pipe(gunzip).pipe(outputStream);
}
function unRar(src) {
    console.log('Rar解压后的', src);
}
function un7z(src) {
    console.log('7z解压后的', src);
}
open('./source.txt.gz');

function zip(src) {
    var gzip = zlib.createGzip();//创建压缩流
    var inputStream = fs.createReadStream(src);
    var outputStream = fs.createWriteStream(src+'.gz');
    inputStream.pipe(gzip).pipe(outputStream);
}
zip('source.txt');
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function bindEvent(elem, type, selector, fn) {
  if (fn === undefined) {
    fn = selector;
    selector = null;
  }
  // ... 剩下相关逻辑
}

bindEvent(elem, 'click', '#div1', fn)
bindEvent(elem, 'click', fn)

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function addEvent(element, type, fn) {
  if (element.addEventListener) {      // 支持 DOM2 级事件处理方法的浏览器
    element.addEventListener(type, fn, false);
  } else if (element.attachEvent) {    // 不支持 DOM2 级但支持 attachEvent
    element.attachEvent('on' + type, fn);
  } else {
    element['on' + type] = fn;         // 都不支持的浏览器
  }
}

var myInput = document.getElementById('myinput');

addEvent(myInput, 'click', function() {
    console.log('绑定 click 事件');
})
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// 移除 DOM 上的事件
function removeEvent(element, type, fn) {
  if (element.removeEventListener) {
    element.removeEventListener(type, fn, false);
  } else if (element.detachEvent) {
    element.detachEvent('on' + type, fn);
  } else {
    element['on' + type] = null;
  }
}

// 获取样式
function getStyle(obj, styleName) {
  if (window.getComputedStyle) {
    var styles = getComputedStyle(obj, null)[styleName];
  } else {
    var styles = obj.currentStyle[styleName];
  }
  return styles;
}

// 阻止默认事件
var preventDefault = function(event) {
  if (event.preventDefault) {
    event.preventDefault();
  } else {                    // IE 下
    event.returnValue = false;
  }
}

// 阻止事件冒泡
var cancelBubble = function(event) {
  if (event.stopPropagation) {
    event.stopPropagation();
  } else {                    // IE 下
    event.cancelBubble = true;
  }
}

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export function createElement(
  context,
  tag,
  data,
  children,
  normalizationType,
  alwaysNormalize
) {
  if (Array.isArray(data) || isPrimitive(data)) {  // 参数的重载
    normalizationType = children
    children = data
    data = undefined
  }
    
  // ...
}

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function createRange(fromRight) {
  return (start, end, step) => {
    // ...
    
    if (end === undefined) {
      end = start
      start = 0
    }
    
    // ...
  }
}

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off: function (types, selector, fn) {
 // ...
 
 if (selector === false || typeof selector === 'function') {
   // ( types [, fn] ) 的使用方式
   fn = selector
   selector = undefined
 }
 
 // ...
}
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jQuery.fn.load = function(url, params, callback) {
  // ...
  
  if (isFunction(params)) {
    callback = params
    params = undefined
  }
  
  // ...
}

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bindReady: function() {
  // ...
    
  // Mozilla, Opera and webkit 支持
  if (document.addEventListener) {
    document.addEventListener('DOMContentLoaded', DOMContentLoaded, false)
        
    // A fallback to window.onload, that will always work
    window.addEventListener('load', jQuery.ready, false)
        
    // 如果使用了 IE 的事件绑定形式
  } else if (document.attachEvent) {
    document.attachEvent('onreadystatechange', DOMContentLoaded)
        
    // A fallback to window.onload, that will always work
    window.attachEvent('onload', jQuery.ready)
  }
    
  // ...
}

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function getDefaultAdapter() {
  // ...

  if (typeof process !== 'undefined' && Object.prototype.toString.call(process) === '[object process]') {
    // Nodejs 中使用 HTTP adapter
    adapter = require('./adapters/http');
  } else if (typeof XMLHttpRequest !== 'undefined') {
    // 浏览器使用 XHR adapter
    adapter = require('./adapters/xhr');
  }
  
  // ...
}

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export default function createStore(reducer, preloadedState, enhancer) {
  if (typeof preloadedState === 'function' && typeof enhancer === 'undefined') {
    enhancer = preloadedState
    preloadedState = undefined
  }
}
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