function deepExtend(child, parent) { child.prototype = Object.create(parent.prototype); child.prototype.constructor = child; for (let key in parent.prototype) { if (typeof parent.prototype[key] === 'object' && parent.prototype[key] !== null) { child.prototype[key] = JSON.parse(JSON.st...
JavaScript 并没有保护 hasOwnProperty 属性名,因此某个对象是有可能存在使用这个属性名的属性,使用外部的 hasOwnProperty 获得正确的结果是需要的: var foo = { hasOwnProperty: function() { return false; }, bar: 'Here be dragons' }; foo.hasOwnProperty('bar'); // 始终返回 false // 如果担心这种...
先看一下Javascript Pattern中关于深度复制的实现: function extendDeep(parent, child) {vari, toStr=Object.prototype.toString, astr="[object Array]"; child= child ||{};for(iinparent) {if(parent.hasOwnProperty(i)) {if(typeofparent[i] ==="object") { child[i]= (toStr.call(parent[i]) ...
// isPlainObject 函数来自于 [JavaScript专题之类型判断(下) ](https://github.com/mqyqingfeng/Blog/issues/30)var class2type = {};var toString = class2type.toString;var hasOwn = class2type.hasOwnProperty;function isPlainObject(obj) { var proto, Ctor; if (!obj || toString.call(obj) ...
What is the purpose of this function call and what functionality would it achieve? In order to understand the logic of extend, it is necessary to understand prototype concept in JavaScript. Let's have a look at some more simple example. ...
In order to understand the logic of extend, it is necessary to understand prototype concept in JavaScript. Let’s have a look at some more simple example. See this simple html source code: function Animal(name) { this.sName = name; console.log("constructor in Animal"); } Animal.protot...
/*扩展函数*/function extend(subClass, superClass) {varF =function() {}; F.prototype= superClass.prototype;//F已成superClass父类subClass.prototype =newF();//子类继承父类的原子subClass.prototype.constructor =subClass; }/*Person类*/function Person(name...
4. Create a javacript function to check that every value. If the javascript time is > SessionTimeOut value show a message box 5. If the user clicks OK, then do post back, else the session will time out. -- I know that there are quite a few holes in the logic, but I believe th...
it will be completely overwritten by a property with the same key in the second or subsequent object. The values are not merged. This can be seen in the example below by examining the value of banana. However, by passingtruefor the first function argument, objects will be recursively merged...
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