• Oct 23, 2025 •opovolotskyi-7e4a
0 likes • 9 views
let state let prevValue function customState(initialValue){ if(state===undefined) { state=initialValue } function setState (newValue){ if(typeof newValue ==="function") { } state=newValue render() } return [state,setState] +(1) setState(2) setState((prev, next) => { return cancelIdleCallback() }) // state
• Oct 15, 2022 •CodeCatch
0 likes • 174 views
import { useState, useEffect, useRef } from "react"; // Usage function App() { // State value and setter for our example const [count, setCount] = useState(0); // Get the previous value (was passed into hook on last render) const prevCount = usePrevious(count); // Display both current and previous count value return ( <div> <h1> Now: {count}, before: {prevCount} </h1> <button onClick={() => setCount(count + 1)}>Increment</button> </div> ); } // Hook function usePrevious(value) { // The ref object is a generic container whose current property is mutable ... // ... and can hold any value, similar to an instance property on a class const ref = useRef(); // Store current value in ref useEffect(() => { ref.current = value; }, [value]); // Only re-run if value changes // Return previous value (happens before update in useEffect above) return ref.current; }
• Oct 22, 2024 •C S
function binarySearch(nums: number[], target: number): number { let left = 0; let right = nums.length - 1; while (left <= right) { const mid = left + Math.floor((right - left) / 2); if (nums[mid] === target) { return mid; } else if (nums[mid] < target) { left = mid + 1; } else { right = mid - 1; } } return left; } function searchInsert(nums: number[], target: number): number { return binarySearch(nums, target); };
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function removeDuplicates(nums: number[]): number { nums.splice(0, nums.length, ...Array.from(new Set(nums))); return nums.length; }; console.log(removeDuplicates([1, 2, 3, 4, 5, 6]))
• Jun 1, 2023 •CodeCatch
0 likes • 5 views
interface Task { id: number; title: string; completed: boolean; } class TaskManager { private tasks: Task[] = []; constructor() {} addTask(title: string) { const taskId = this.tasks.length + 1; const task: Task = { id: taskId, title, completed: false, }; this.tasks.push(task); } markTaskAsComplete(taskId: number) { const task = this.tasks.find((task) => task.id === taskId); if (task) { task.completed = true; } } markTaskAsIncomplete(taskId: number) { const task = this.tasks.find((task) => task.id === taskId); if (task) { task.completed = false; } } listTasks() { console.log('Tasks:'); this.tasks.forEach((task) => { console.log(`${task.id}. [${task.completed ? 'X' : ' '}] ${task.title}`); }); } } // Example usage: const taskManager = new TaskManager(); taskManager.addTask('Buy groceries'); taskManager.addTask('Pay bills'); taskManager.addTask('Clean the house'); taskManager.listTasks(); // Output: // Tasks: // 1. [ ] Buy groceries // 2. [ ] Pay bills // 3. [ ] Clean the house
• Nov 21, 2023 •AustinLeath
0 likes • 25 views
// Print Hello, World! console.log("Hello, World!");