在JavaScript中,instanceof 操作符用于检测一个对象是否在其原型链的原型构造函数的 prototype 属性所指向的原型对象上。当你遇到“function has non-object prototype 'undefined' in instanceof check”这样的错误时,意味着你试图使用 instanceof 来检查一个对象的原型链,但发现该对象的原型(即 __proto__ 属性)是...
原本可以正常打包部署运行,前两天加了些新功能,再打包就遇到这个问题,其意为:函数在instanceof check中具有非对象原型“undefined” TypeError: Function has non-object prototype 'undefined' in instanceof check at [Symbol.hasInstance] (<anonymous>) at Function.o (index-23b873a3.js:9:77458) at commonFu...
var hasStrictMode = (function () {"use strict";return this == undefined;}());var isStrictMode = function () {return this === undefined;};var getGlobal = function () {if (typeof self !== 'undefined') { return self; }if (typeof window !== 'undefined') { return window; }if ...
it always has at least the following properties: Object object Function object Array object String object Boolean object Number object Date object Math object Value properties */ Array.prototype.mymethod = function(number) { var result
Call of non-function :调用未定义的函数 Call to function with no prototype :调用函数时没有函数的说明 Cannot modify a const object :不允许修改常量对象 Case outside of switch :漏掉了case 语句 Case syntax error :Case 语法错误 Code has no effect :代码不可述不可能执行到 ...
(); // add new property to person1 person1.age = 20; // add a method to person1 object person1.greet = function () { return "hello"; } console.log(person1.age); // 20 console.log(person1.greet()); // hello console.log(person2.age); // undefined console.log(person2.greet...
it’s definition has no effect on variable object; and is created at the code execution stage. 在源码中须出现在表达式的位置 有可选的名称 不会影响变量对象 在代码执行阶段创建 The main feature of this type of functions is that in the source code they are always in theexpression position. Her...
Verifying That Windows DVD Maker Has the Right to Run on a Specific Version of Windows Vista Token Element (Three Child Elements) TextTFXToken Element MainToScenes6Transition Element Transition and Effect Objects Provided by Windows Movie Maker MDM_Policy_Config01_ControlPolicyConflict02 class (Window...
has anobligatoryname; in the source code position it is positioned: either at theProgramlevel or directly in the body of another function(FunctionBody); is created onentering the contextstage; influencesvariable object; and is declared in the following way: ...
逻辑操作OR(||)当第一个操作数是false时就返回第二个参数。因为函数调用的时候没有提供参数,那么就是隐式的将函数参数设置为undefined,逻辑操作OR经常用来为缺失的参数提供默认值。这种方式有一个缺点,timeout有可能在调用的时候传递参数0,但是由于OR操作符中0等同于false,timeout最终的值会被2000所替代。