function flattenObject(obj: any): any { return Object.keys(obj).reduce((acc, key) => { if (typeof obj[key] === 'object' && !Array.isArray(obj[key])) { const flattenedObject = flattenObject(obj[key]); Object.keys(flattenedObject).forEach((nestedKey) => { acc[`${key}.${nest...
in关键字用来检查一个属性是否属于一个对象,如果这个条件为true,TypeScript就会默认这个变量的类型是我们指定的类型。例如: type Student = { name: string; major: string; gpa: number; } function printStudentInfo(student: Student, key: string) { if (key in student) { console.log(student[key]); }...
您可以使用Array.from和reduce编写更简洁的代码 注意:如果你想添加1 + 2 + 3 + 4,如果你说是1-4,那么你可以替换 Array.from({ length: end - start + 1 }, (_, i) => i + start) const sumAll = function (a, b) { const [start, end] = a > b ? [b, a] : [a, b]; return ...
问如何正确使用TypeScript和Array.prototype.reduce？EN这里有一个使用useState在React组件中使用的示例，以...
[k:string]:T}// Array.prototype.map, but for DictfunctionmapDict<T,S>(input:Dict<T>,transform:(item:T,key:string)=>S):Dict<S>{constobj:Dict<S>={};for(letxininput){obj[x]=transform(input[x],x);}returnobj;}// Array.prototype.filter, but for DictfunctionfilterDict<T>(input:...
functionisBigEnough(element, index, array) {return(element >=10); }varpassed = [2,5,8,1,4].some(isBigEnough);// passed is falsepassed = [12,5,8,1,4].some(isBigEnough);// passed is true filter() var newArr = arr.filter(callback[, thisArg]) ...
Stream of Function[] 您似乎希望reduce使用andThen函数。假设conversions不能为空,可以执行以下操作: static <T> T applyConversions(T value, Function<T, T>... conversions) { return Arrays.stream(conversions).reduce(Function::andThen).get().apply(value);} 如果它可以为空,则需要决定当它为空时返回...
arr.reduce(callback,[initialValue]) reduce 为数组中的每一个元素依次执行回调函数callback 不包括数组中被删除或从未被赋值的元素,接受四个参数: /** * callback {function(prev, cur, index, arr)} * pr ... js 数组 回调函数 赋值 一维数组 转载 mob604756eb6938 2021-08-02 18:09:00 146阅读...
Updated Nov 6, 2023 TypeScript mfix22 / morphmorph Sponsor Star 28 Code Issues Pull requests 😱 Isomorphic transformations. Map, transform, filter, and morph your objects functional isomorphic mapping filter transformations reduce morph function-composition isomorphic-transformations Updated Jan 3,...
acc, []);} 测试 filter([null, false, 1, 0, '', () => {}, NaN], val => !!val);// [1, () => {}]some some当⽬标数组为空返回false，故初始值为false。function some(arr, predicate) { return arr.reduce((acc, val, idx) => acc || predicate(val, idx, arr), false)