JavaScript Array & Object Snippets | Modern ES6+ Logic Grids

Home / Coding Reference / JS Logic ES6+ Logic Standard JavaScript Array & Object Snippets Verified logic grids for efficient data manipulation and object handling in modern JavaScript. Array Manipulation Method Code Snippet Result / Use Case .map() const doubled = arr.map(x => x * 2); Creates a new array by transforming every element. .filter() const active = users.filter(u => u.isActive); Returns a subset of elements that pass a test. .reduce() const total = prices.reduce((a, b) => a + b, 0); Reduces array to a single value (sum, average, etc). Object & Spread Logic Logic Code Snippet Result / Use Case Spread (...) const newObj = { ...oldObj, status: 'done' }; Clones an object while overriding specific properties. Destructuring const { name, age } = user; Extracts properties into clean, standalone variables. Keys / Values Object.keys(myObj).length; Efficient way to check object size or iterate keys. Immutability Tip: Modern JS frameworks (like React) prefer .map() and .filter() because …