然而,在使用箭头函数作为数组方法的回调函数时,如果函数体内预期应该返回一个值但实际上没有返回,JavaScript引擎会抛出一个错误,提示“expected to return a value in arrow function array-callback-return”。 这个错误通常发生在以下几种情况: 数组迭代方法:如forEach、map、filter、reduce等,这些方法接受一个回调...
我得到了一个错误,expected to return a value at the end of the arrow function error我应该如何解决这个问题?发布于 2 月前 ✅ 最佳回答: lint规则希望您显式返回未定义的:nodeValues.map((o) => { if (o.displayName === "Form") { return o.props.code; } else { return undefined; } });...
The error prompt “Array.prototype.map() expects a return value from Arrow Function” message may pop up in Javascript. There are several scenarios where you may face this problem and there are mutiple wyas of bypassing this problem. Generally, while using the “Array.prototype.map()” functi...
Why do I get this error? Can someone please help me? "Expected to return a value at the end of async arrow function consistent-return." I use it on an onChange since I would like the URL put in the input to be used. const handleChange = ...
Example 1: Arrow Function With No Argument If a function doesn't take any argument, then you should use empty parentheses. For example, constsayHello =()=>"Hello, World!"; // call the arrow function and print its return valueconsole.log(sayHello());// Output: Hello, World!
A function that accepts up to three arguments. forEach calls the callbackfn function one time fo...
self.age = 0; setInterval(function growUp() { // The callback refers to the `self` variable of which // the value is the expected object. self.age++; }, 1000); } 或者是,透過綁定函數的作法來綁定 this 變數到 growUp 函數。 不過現在箭頭函數會自動將 this 變數綁定到其定義時所在的物件,...
function Prefixer(prefix) { this.prefix = prefix; } Prefixer.prototype.prefixArray = function (arr) { var that = this; // (A) return arr.map(function (x) { return that.prefix + x; }); }; Now Prefixer works as expected:> var pre = new Prefixer('Hi '); > pre.prefixArray(['...
A function that accepts up to three arguments. forEach calls the callbackfn function one time fo...
of concept we can again try logging this from within our arrow function. We’ll create a variable called that in our Counter function. We’ll then log out true if the value of this in our setInterval function is equal to the value of this (via that ) in the parent Counter function:...