I've written some code to render repeating elements in ReactJS, but I hate how ugly it is. render: function(){ var titles = this.props.titles.map(function(title) { return <th>{title}</th>; }); var rows = this.props.rows.map(function(row) { var cells = []; for (var i in row) { cells.push(<td>{row[i]}</td>); } return <tr>{cells}<
我写了一些代码来渲染ReactJS中的重复元素，但我讨厌它有多丑。 render: function(){ var titles = this.props.titles.map(function(title) { return <th>{title}</th>; }); var rows = this.props.rows.map(function(row) { var cells = []; for (var i in row) { cells.push(<td>{row[i]}</td>); } return <tr>{cells}</tr>; }); return ( <t
I'm looking for any alternatives to the below for creating a JavaScript array containing 1 through to N where N is only known at runtime. var foo = []; for (var i = 1; i <= N; i++) { foo.push(i); } To me it feels like there should be a way of doing this without the loop. If I get what you are after, you want an array of numbers 1..n that you can later loop through. If this is all
我正在寻找下面的任何替代方法来创建一个包含1到N的JavaScript数组，其中N只在运行时才为人所知。 var foo = []; for (var i = 1; i <= N; i++) { foo.push(i); } 对我来说，感觉就像没有循环一样，应该有这样做的方法。 如果我得到你以后的东西，你需要一个数组1..n ，你可以稍后循环。 如果这是你所需要的，你可以这样做吗？ var foo = new Array(45);//create an empty array with length 45 那么当你想使用它
This question already has an answer here: Loop inside React JSX 38 answers Use a map so you're actually returning the elements. A foreach doesn't return anything. Your use of && was also invalid. var graph = <div className={"chartContent"}> <div className="panel"> {DataRows.map(entry => <div key={ent
这个问题在这里已经有了答案： 循环内React JSX 38答案 使用地图，以便实际返回元素。 一个foreach不会返回任何东西。 您使用&&也是无效的。 var graph = <div className={"chartContent"}> <div className="panel"> {DataRows.map(entry => <div key={entry.id} className="col-sm-2 graphPanel graphPanelExtra">
This question already has an answer here: Loop inside React JSX 38 answers for loop in react 1 answer You can run the loop before the rendering (note that there's an error in your for loop) var lis = []; for (var i=0; i<10; i++) { lis.push(<li><a href="#">{i + 1}</a></li>); } var Pagination = React.createClass({ render: function(){ return(
这个问题在这里已经有了答案： 循环内React JSX 38答案 for循环回答1答案 您可以在渲染之前运行循环（请注意， for循环中有错误） var lis = []; for (var i=0; i<10; i++) { lis.push(<li><a href="#">{i + 1}</a></li>); } var Pagination = React.createClass({ render: function(){ return( <div class="text-center"> <ul class=
It would be very helpful, if someone explains the working of a curry function. I have read many examples, but not able to grasp it properly. Is it anyhow related to closure. Currying is just technique, that can make use of any language feature (eg closures) to achieve the desired result, but it is not defined what language feature has to be used. As of that currying does not require to make
如果有人解释咖喱功能的工作，这将是非常有帮助的。 我读过很多例子，但无法正确掌握它。 它是否与关闭有关。 柯里化只是一种技巧，它可以利用任何语言特征（例如闭包）来达到预期的效果，但是它没有定义要使用哪种语言特征。 因为咖喱并不需要使用关闭（但在大多数情况下会使用关闭） 这里有一个使用咖啡的小例子，有和没有使用闭包。 通过使用闭包： function addition(x,y) { if (typeof y === "undefined" ) {
Consider the following code: function nepaliBuddha() { var a = 20; return function buddhaNepal() { console.log(a); } } var closure = nepaliBuddha(); closure(); // logs 20 Now when we invoke closure output is 20 . This proves that the internal scope property ( [[scope]] ) was assigned to the inner function where it was defined or say when declared.If this wasn't assi
考虑下面的代码： function nepaliBuddha() { var a = 20; return function buddhaNepal() { console.log(a); } } var closure = nepaliBuddha(); closure(); // logs 20 现在当我们调用closure输出是20 。 这证明内部作用域属性（ [[scope]]被分配给内部函数，在该内部函数中定义或声明了内部函数。如果未在声明中分配此属性，则无法在调用时记录20不同的背景 调用closure()函数上下文的作用域链
I understand that every function in JavaScript is a first-class object and it has an internal property [[scope]] which hosts the binding records of the function's free variables. However, there are two special cases. Is the function created by Function constructor also a closure? The function object created by Function constructor is special, because its [[scope]] may not refer to the lex
我明白，JavaScript中的每个函数都是第一类对象，并且它有一个内部属性[[scope]]，它托管函数自由变量的绑定记录。 但是，有两种特殊情况。 函数构造函数创建的函数是否也是闭包？ 由Function构造函数创建的函数对象是特殊的，因为它[[scope]]可能不会引用其外部函数的词法环境，而只能引用全局上下文。 例如， var a = 1; var fn = (function outer() { var a = 2; var inner = new Function('alert(a); ');
Hey i came across this video on youtube http://www.youtube.com/watch?v=KRm-h6vcpxs which basically explains IIFEs and closures. But what I am not understanding is whether i need to return a function in order to call it a closure. Ex function a() { var i = 10; function b() { alert(i); } } in this case can i call it a closure as it is accessing the 'i' variable fro
嘿，我在YouTube上看到这个视频http://www.youtube.com/watch?v=KRm-h6vcpxs 这基本解释了IIFE和闭包。 但我不明白的是，是否需要返回一个函数才能将其称为闭包。 防爆 function a() { var i = 10; function b() { alert(i); } } 在这种情况下，我可以将它称为闭包，因为它正在从外部函数的作用域访问'i'变量，或者是否需要返回像这样的函数 return function b(){alert(i);} 返回函数不会改
I have a very trivial question. For a simple loop with setTimeout, like this: for (var count = 0; count < 3; count++) { setTimeout(function() { alert("Count = " + count); }, 1000 * count); } console gives an output like this: Count = 3 Count = 3 Count = 3 Not sure why the output like this. Anyone could explain, please? This has to do with how scoping and hoisting is bei
我有一个非常微不足道的问题。 对于setTimeout的简单循环，如下所示： for (var count = 0; count < 3; count++) { setTimeout(function() { alert("Count = " + count); }, 1000 * count); } 控制台提供如下输出： Count = 3 Count = 3 Count = 3 不知道为什么这样的输出。 任何人都可以解释，请吗？ 这与JavaScript中如何处理范围和提升有关。 代码中会发生什么，JS引擎会将您的代码修改为： var
This question already has an answer here: JavaScript closures vs. anonymous functions 12 answers The setTimeout is an asynchronous call. That means, it gets executed only after the whole loop gets executed. In your JS Interpreter, it would be like this: 1: for loop. // i = 0 2: send setTimeout #1. increment i. // i = 1 3: send setTimeout #2. incr
这个问题在这里已经有了答案： JavaScript闭包与匿名函数12个答案 setTimeout是一个异步调用。 这意味着，它只有在整个循环得到执行后才会执行。 在你的JS解释器中，它会是这样的： 1: for loop. // i = 0 2: send setTimeout #1. increment i. // i = 1 3: send setTimeout #2. increment i. // i = 2 4: send setTimeout #3. increment i. // i = 3 5: send se