prototype,'myReduce',{ value:function (callback) { //特殊处理 if (this===null){ throw new TypeError('reduce called on null or undefined!'); } if (typeof callback!=='function'){ throw new TypeError(callback + 'is not a function!'); } //o是进行reduce的对象 let o=Object(this);...
function reduce(array, callback, initialValue) { // step #1. Create our 'store' let store = initialValue || 0; // step #2. Iterate over 'array' and save return value // of 'callback' to 'store' for(let i = 0; i < array.length; i++) { store = callback(store, array[i])...
Polyfill是JavaScript社区中的一个术语,指的是一段代码,其目的是模拟或实现新的JavaScript API或特性,以便在不支持这些新特性的旧版浏览器中使用。开发者可以使用最新的语法和功能,而不必担心兼容性问题。 ES5的新增特性与Polyfill Array Methods:ES5引入了诸如forEach,map,filter,reduce,every,some等数组方法。如果目标...
reduce在英文中译为“减少; 缩小; 使还原; 使变弱”,MDN对方法直述为:“The reduce method applies a function against an accumulator and each value of the array (from left-to-right) to reduce it to a single value.” 我并不打算对他直接翻译,因为这样会变的更加晦涩难懂。 我们看他的使用语法: ...
好了,以上例子仅用于体现 JavaScript 语法的简单(笑 不过也确实写 try/catch 嵌套写烦了,偶然发现了这个提案,眼前一亮,真的简洁直观🥰 介绍`?=` 运算符 安全赋值运算符 () 提案符旨在简化代码中的错误处理,使代码更易于阅读,特别是在处理可能失败或抛出错误的函数时。当使用运算符时,它会检查函数或操作是否成...
(-pure)/es|stable|actual|full/iterator/for-each core-js(-pure)/es|stable|actual|full/iterator/from core-js(-pure)/es|stable|actual|full/iterator/map core-js(-pure)/es|stable|actual|full/iterator/reduce core-js(-pure)/es|stable|actual|full/iterator/some core-js(-pure)/es|stable|...
isValueSet) { throw new TypeError('Reduce of empty array with no initial value'); } return value; }; } #Array.prototype.forEach() if (!Array.prototype.forEach) { Array.prototype.forEach = function(callback, thisArg) { var T, k; if (this == null) { throw new TypeError(' this ...
Improved Security: Reduce the risk of overlooking error handling, thereby enhancing the overall security of the code. 改进安全性:降低忽略错误处理的风险,从而提高代码的整体安全性。 How often have you seen code like this? 你见过这样的代码多少次了?
prototype.forEach; Array.prototype.includes; Array.prototype.indexOf; Array.prototype.keys; Array.prototype.lastIndexOf; Array.prototype.map; Array.prototype.reduce; Array.prototype.reduceRight; Array.prototype.some; Array.prototype.toLocaleString; Array.prototype.values; Date Polyfill: Date.prototype....
Extra options for shadow-dom OptionDescription experimental You can pass the experimental option to shadow-dom (or any of its aliases such as web-components) to base it on some experimental features that may reduce bugs in older browsers such as IE and Edge <= 15. lit If you're going to...