Removing Promise constructor wrappers As @Peilonrayz mentioned in his comment, we can return the promises directly instead of wrapping them in Promise constructors. From theMDN: Promise docs: The constructor is primarily used to wrap functions that do not already support promises. Since we are al...
// ✅ 1. 注册自定义组件(Autonomous custom elements / 自主自定义元素)window.customElements.define('wcui-button', wcuiButton) // ✅ 2. 注册自定义组件(Customized built-in elements / 定制的内置元素)window.customElements.define('wcui-button', wcuiButton, {extends:'div'}) // js 使用方式...
按照MDN 的描述:回调函数是作为参数传给另一个函数的函数,然后通过在外部函数内部调用该回调函数以完成某种操作。 让我用人话解释一下,回调函数是一个函数,将会在另一个函数完成执行后立即执行。回调函数是一个作为参数传给另一个 JavaScript 函数的函数。这个回调函数会在传给的函数内部执行。 在JavaScript 中函数被...
Promise是JS对象,它们用于表示一个异步操作的最终完成 (或失败), 及其结果值.查看MDN 您可以通过使用回调方法或使用Promise执行异步操作来获得结果。但是两者之间有一些细微的差异。 CallBack 和Promise之间的区别 两者之间的主要区别在于,使用回调方法时,我们通常只是将回调传递给一个函数,该函数将在完成时被调用以获取...
我必须承认我对JavaScript还比较新,这是我见过的关于JS代理函数最好的解释之一。 - Misha Nasledov 1 在ES6中引入了箭头函数,它们不会绑定自己的this。 MDN参考。因此,使用箭头语法创建匿名函数可能是目前最简单的克服此问题的方法。它目前受到所有主要浏览器的支持,除了IE。 - Jon F. 0 关键字 'this' ...
The solution uses a for loop but I just couldn't find anything in MDN - Iteration Protocols that refers to yield within callbacks. I'm going to guess the answer is just don't do that but thanks in advance if anyone has the time or inclination to provide an explanation! Code: function...
Partner telemetry is getting an error, TypeError: e[0] is undefined in useMessageBarReflow.js. There are two instances of accessing the zeroth element of an array in this file: entries borderBoxSize According to MDN's example, borderBoxSize may be empty: https://developer.mozilla.org/en-...
在空闲的时候加载些东西,可以看看 qiankun 的例子,用来预加载 js 和 css functionprefetch(entry:Entry,opts?:ImportEntryOpts):void{ if(!navigator.onLine||isSlowNetwork) { // Don't prefetch if in a slow network or offline return; } requestIdleCallback(async()=>{ ...
There is another use case: when scrolling to particular element it is common that one must take in an account fixed-position headers. Unfortunately the very widespread solution is to have resizable fixed headers. E.g. tall header in the initial position and minimal header after a page was scr...
重学前端性能优化: requestAnimationFrame & requestIdleCallback All In One 微任务队列, CPU 调度,时间分片 requestAnimationFrame cancelAnimationFrame requestIdleCallback cancelIdleCallback https://developer.mozilla.org/en-US/docs/Web/API/window/requestAnimationFrame ...