forEach方法第二个参数就是当前循环项的index值。 products.forEach(function(product,index) { console.log(index, product); }); 也就等价于for循环中的写法: for (var i = 0; i < products.length; i++) { console.log(i, products[i]); } 唯一美中不足的就是forEach不支持中断循环,如果不需要...
JavaScript's for each loop is a quick and easy way to iterate over an array. Used as an alternative to the for loop, it can make code more declarative and easy to read. javascript For many developers, JavaScript acts as introduction to the functional programming paradigm. And if you've ...
function asyncFunction(item) { return new Promise((resolve, reject) => { // 异步操作 // 在操作完成后调用resolve或reject // resolve(value)表示操作成功,返回value // reject(error)表示操作失败,返回error }); } const array = [1, 2, 3, 4, 5]; const promises = []; array.forEach(ite...
for...of 语句执行一个循环,该循环处理来自可迭代对象的值序列。可迭代对象包括内置对象的实例,例如 Array、String、TypedArray、Map、Set、NodeList(以及其他 DOM 集合),还包括 arguments 对象、由生成器函数生成的生成器,以及用户定义的可迭代对象。
Expression 1 sets a variable before the loop starts (let i = 0). Expression 2 defines the condition for the loop to run (i must be less than 5). Expression 3 increases a value (i++) each time the code block in the loop has been executed. ...
问从forEachloop Javascript中的异步函数返回值EN所以我有一个对象，里面有'n‘个元素，我必须进入每个...
jsCopy to Clipboard function logThis() { "use strict"; console.log(this); } [1, 2, 3].forEach(logThis); // undefined、undefined、undefined 一些API 允许你为回调函数的调用设置一个 this 值。例如,所有的迭代数组方法和相关的方法,如Set.prototype.forEach(),都接受一个可选的 thisArg 参数。js...
foreach (Product p in data) { resultRow = ""; if (sensitivity == "Not Case Sensitive" && p.desc.IndexOf(filter, StringComparison.CurrentCultureIgnoreCase) >= 0) { resultRow = p.id + " " + p.desc; ++count; } else if (sensitivity == "Case Sensitive" &...
Loop [fe] forEach $myArray$.forEach(function($item$) { $end$}); Function [afn] anonymous function function($arguments$) { $end$} [pr] prototype $object$.prototype.$methodName$ = function($arguments$) { $end$} [call] function call $methodName$.call($context$, $arguments$) [apply...
forEach((jedi) => { jedi.father = 'vader'; }); // good const reaction = 'No! That’s impossible!'; (async function meanwhileOnTheFalcon() { // handle `leia`, `lando`, `chewie`, `r2`, `c3p0` // ... }()); // good function foo() { return 'search your feelings, you ...