function fetchMessages(username) { return fetch(`https://example.com/api/messages/${username}`) .then(response => response.json());}function getUsername(person) { return person.username;}function chainedFetchMessages(p, username) { // In this function, p is a promise. We wait for it ...
AI代码解释 functionkeyByUsernameReducer(acc,person){return{...acc,[person.username]:person};}constpeopleObj=peopleArr.reduce(keyByUsernameReducer,{});console.log(peopleObj);// ⦘ {// "glestrade": {// "username": "glestrade",// "displayname": "Inspector Lestrade",// "email": "glestra...
functionadd(a,b){ returna+b; } functionmultiply(a,b){ returna*b; } constsampleArray=[1,2,3,4]; constsum=sampleArray.reduce(add,0); console.log(‘Thesum to...
The reduce method executes a reducer function on each element of the array. This results in a single output value calculated from the elements. The reducer function takes four arguments: accumulator, current value, current index, and source array. The accumulator accumulates the callback's return...
reduce(function(accumulator, currentValue, currentIndex, array){ return accumulator + currentValue; });查看中间结果也是可以的[0, 1, 2, 3, 4].reduce(function (accumulator, currentValue, currentIndex, array) { stepRes = accumulator + currentValue console.log('accumulator,currentValue,currentIndex,...
}functiongetLastSeen(x) {returnx.lastSeen; }functiongreater(a, b) {return(a > b) ? a : b; }constpeopleWithEmail = peopleArr.filter(notEmptyEmail);constlastSeenDates = peopleWithEmail.map(getLastSeen);constmostRecent = lastSeenDates.reduce(greater,'');console.log(mostRecent);// ⦘...
代码语言:javascript 代码运行次数:0 运行 AI代码解释 function Difference(arr = [], oarr = []) { return arr.reduce((t, v) => (!oarr.includes(v) && t.push(v), t), []); } 代码语言:javascript 代码运行次数:0 运行 AI代码解释 const arr1 = [1, 2, 3, 4, 5]; const arr2 = ...
reducer(或者称之为callbackFunction) 可以被比喻做工具(榔头) reduce() reducer()可以被比喻为工人(拿着榔头的工人) 执行过程和效果: 可以比喻为工人操纵榔头击打钉子到模板中,次数类比为数组中的元素数目,钉子钉入的深度视为accumulator(操作的结果);调用了array.size次后,得到结果(钉入的长度为全长) ...
Returns true if any of the elements in the array pass the test, otherwise it returns false JavaScript Version: 1.8More ExamplesExample Round all the number is an array, and display the sum: Try itSum of numbers in array: var numbers = [15.5, 2.3, 1.1, 4.7];function getSum(total, num...
function()Required. A function to be run for each element in the array. Reducer function parameters: totalRequired. TheinitialValue, or the previously returned value of the function. currentValueRequired. The value of the current element.