• Nov 19, 2022 •CodeCatch
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//JavaScript program to swap two variables //take input from the users let a = prompt('Enter the first variable: '); let b = prompt('Enter the second variable: '); //using destructuring assignment [a, b] = [b, a]; console.log(`The value of a after swapping: ${a}`); console.log(`The value of b after swapping: ${b}`);
• Jan 26, 2023 •AustinLeath
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function printHeap(heap, index, level) { if (index >= heap.length) { return; } console.log(" ".repeat(level) + heap[index]); printHeap(heap, 2 * index + 1, level + 1); printHeap(heap, 2 * index + 2, level + 1); } //You can call this function by passing in the heap array and the index of the root node, which is typically 0, and level = 0. let heap = [3, 8, 7, 15, 17, 30, 35, 2, 4, 5, 9]; printHeap(heap,0,0)
const nums = [1, 2, 3]; const strs = Array.from('est'); nums.push(6); nums.push(4, 9); strs.unshift('t'); nums.length; // 6 nums[nums.length - 1]; // 9 strs[0]; // 't' strs[2]; // 's' nums.slice(1, 3); // [2, 3] nums.map(n => n * 2); // [2, 4, 6, 12, 8, 18] nums.filter(n => n % 2 === 0); // [2, 6, 4] nums.reduce((a, n) => a + n, 0); // 25 strs.reverse(); // ['t', 's', 'e', 't'] strs.join(''); // 'test' const nums = new Set([1, 2, 3]); nums.add(4); nums.add(1); nums.add(5); nums.add(4); nums.size; // 5 nums.has(4); // true nums.delete(4); nums.has(4); // false [...nums]; // [1, 2, 3, 5] nums.clear(); nums.size; // 0 const items = new Map([ [1, { name: 'John' }], [2, { name: 'Mary' }] ]); items.set(4, { name: 'Alan' }); items.set(2, { name: 'Jeff' }); items.size; // 3 items.has(4); // true items.get(2); // { name: 'Jeff' } items.delete(2); items.size; // 2 [...items.keys()]; // [1, 4] [...items.values()]; // [{ name: 'John' }, { name: 'Alan' }] items.clear(); items.size; // 0
• Apr 10, 2025 •hasnaoui1
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const express = require('express') const mongoose = require('mongoose') const cors = require('cors') const dotenv = require('dotenv') const server = express() dotenv.config() server.use(express.json()) server.get('/' , (req , res)=>{ res.send('Hello') }) //4.lancement du serveur server.listen(process.env.PORT , ()=>{ console.log('server run on http://localhost:'+process.env.PORT) })
• Feb 5, 2021 •LeifMessinger
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class Timer{ start(){ this.startTime = Date.now(); } stop(){ const dt = Date.now() - this.startTime; console.log(dt); return dt; } getExecTime(fun, asynchronous){ return asynchronous ? this.getAsyncExecTime(fun) : this.getSyncExecTime(fun); } getSyncExecTime(fun){ this.start(); fun(); return this.stop(); } async getAsyncExecTime(fun){ this.start(); await fun(); return this.stop(); } static average(fun, numTimes, asynchronous = false){ const times = []; const promises = []; let timer = new Timer(); if(asynchronous){ for(let i = 0; i < numTimes; i++){ timer.getAsyncExecTime(fun); } }else{ for(let i = 0; i < numTimes; i++){ timer.getSyncExecTime(fun); } } return (times => times.reduce(((sum, acc) => sume + acc), 0) / times.length); } static async timeAsync(fun, numTimes){ if(numTimes <= 1) return new Timer().getAsyncExecTime(fun); const promises = []; let timer = new Timer(true); for(let i = 0; i < numTimes; i++){ promises.push(fun().catch((e)=>{})); } try{ await Promise.all(promises).catch((e)=>{}); }catch(e){ //do absolutely nothing } return timer.stop(); } constructor(start = false){ if(start) this.start(); } }
arr = [] // empty array const isEmpty = arr => !Array.isArray(arr) || arr.length === 0; // Examples isEmpty([]); // true isEmpty([1, 2, 3]); // false