错误信息“array.from is not a function”表明你尝试在一个变量(可能是未定义的或不是一个对象)上调用from方法,但这个变量并没有from方法。这通常是因为方法名书写错误。 2. 指出正确的函数名 在JavaScript中,正确的方法名应该是Array.from,而不是array.from。Array.from是一个静态方法,用于将类数组对象或可迭...
但我得到了 TypeError: elements.forEach is not a function奇怪的是,如果我 console.log(elements) 在Chrome 开发控制台中,它就像一个带有一堆 input 对象的数组。它不显示对象的 Object 表示法,并且所有键都是整数。我在想这是某种伪数组,但我什至不知道如何找到它。编辑:简短的回答它不是一个数组,它是一...
There are four areas in the this code where the following throws a forEach. It is not a function because parent.children is not an array. Instead, it is an HTMLCollection and as such doesn't have forEach method. obj[that.children].forEac...
Array.prototype.forEach = function forEach(callback, thisArg) { var T, k; if (this == null) { throw new TypeError("this is null or not defined"); } var O = Object(this); var len = O.length >>> 0; if (typeof callback !== "function") { throw new TypeError(callback + "...
function F(x) { const integerX = Math.trunc(x) return Math.max(integerX, 0) } 根据规范步骤实现 forEach() 到这里在规范步骤中用到的所有抽象操作都已经实现,现在只需按规范步骤写出 forEach 代码即可。 Array.prototype.myForEach = function (callbackfn, thisArg) { // 1. 将 this 值转换为对...
_includes = function(searchElement,fromIndex){ if (this === null) { throw new TypeError('"this" is null or not defined'); } let that = Object(this),len = that.length >>> 0,param = arguments,index = fromIndex | 0; if(len === 0){return false;} startIndex = Math.max(index ...
* @param {function} callback a callback * @throws {TypeError} when callback is not callable object * @example [1,2,3].forEach(function(el){ console.log(el); }); */ if(!Array.prototype.forEach){ Array.prototype.forEach =function(callback, thisArg){ ...
forEach() 被调用时,不会改变原数组,也就是调用它的数组(尽管 callback 函数在被调用时可能会改变原数组)。(此处说法可能不够明确,具体可参考EMCA语言规范:'forEach does not directly mutate the object on which it is called but the object may be mutated by the calls to callback function.',即 for...
prototype.forEach) { Array.prototype.forEach = function forEach(callback, thisArg) { var T, k; if (this == null) { throw new TypeError("this is null or not defined"); } var O = Object(this); var len = O.length >>> 0; if (typeof callback !== "function") { throw new ...
TypeError: t.replace is not a function at Array.forEach () 环境信息 👽 Taro v3.6.34 Taro CLI 3.6.34 environment info: System: OS: macOS 12.6 Shell: 5.8.1 - /bin/zsh Binaries: Node: 18.20.4 - ~/.nvm/versions/node/v18.20.4/bin/node Yarn: 1.22.21 - /usr/local/bin/yarn npm...