log(countOccurrences(fruits, 'banana')); // 输出: 3 console.log(countOccurrencesWithReduce(fruits, 'banana')); // 输出: 3 2. 对数组中的元素进行求和 如果我们需要计算数组中所有元素的和,可以使用reduce方法。 示例代码: javascript function sumArray(arr) { return arr.reduce((sum, item) =&...
1 2 const countOccurrences = (arr, value) => arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0); countOccurrences([1, 2, 3, 2, 2, 5, 1], 1);循环数组,每遇到一个值与给定值相等,即加1,同时将加上之后的结果作为下次的初始值。
数组(Array):JavaScript中的一种数据结构,用于存储一系列的元素。 计数(Count):统计特定元素在数组中出现的次数。 实现方式 使用for循环:遍历数组,每次遇到目标元素时增加计数器。 代码语言:txt 复制 function countOccurrences(arr, target) { let count = 0; for (let i = 0; i < arr.length; i++) { ...
/** * @param { array } arr * @param {*} value */export function countOccurrences(arr, value) { return arr.reduce((a, v) => v === value ? a + 1 : a + 0, 0);}加法函数(精度丢失问题)/** * @param { number } arg1 * @param { number } arg2 */export function add(arg1...
constcountOccurrences=(arr,val)=>arr.reduce((a,v)=>(v===val?a+1:a),0);countOccurrences([1,1,2,1,2,3],1);// 3 12. `deepFlatten`:递归扁平化数组 代码语言:javascript 复制 constdeepFlatten=arr=>[].concat(...arr.map(v=>(Array.isArray(v)?deepFlatten(v):v)));deepFlatten([...
reserved (default: [])— Pass an array of identifiers that should be excluded from mangling. Example: ["foo", "bar"]. toplevel (default: false)— Pass true to mangle names declared in the top level scope. Examples: // test.js var globalVar; function funcName(firstLongName, anotherLong...
Write a function that takes an array (a) as argument Remove the first 3 elements of 'a' Return the result 我的提交(作者答案) functionmyFunction(a) {returna.slice(3);} 涉及知识(slice()方法)# Array.prototype.slice()# 返回一个新的由begin和end决定的原数组的浅拷贝数组对象 ...
pure_funcs (default: null)— You can pass an array of names and UglifyJS will assume that those functions do not produce side effects. DANGER: will not check if the name is redefined in scope. An example case here, for instance var q = Math.floor(a/b). If variable q is not used...
Array.flatMap() let array = [1, 2, 3, 4, 5]; array.map(x => [x, x * 2]); 1. 2. 3. array 现在的结果: [Array(2), Array(2), Array(2)] 0: (2)[1, 2] 1: (2)[2, 4] 2: (2)[3, 6]
functionfindAllOccurrences(arr, target) {vartemp =[]; arr.forEach(function(val,index){ val!== target ||temp.push(index); });returntemp; } findAllOccurrences(['abcdefabc'],'a'); 13.js 代码中 parseInt 的调用方式,使之通过全部测试用例 ...