Array Methods Categories

Array methods in JavaScript are grouped into three categories based on their behavior:

• Mutator methods – modify the original array (e.g., push, pop, splice).
• Accessor methods – return a new value or a new array without modifying the original (e.g., concat, slice, includes).
• Iteration methods – iterate over array elements and perform operations (e.g., forEach, map, filter, reduce).

Code Example

const arr = [1, 2, 3];

// Mutator (changes original)
arr.push(4);
console.log(arr); // [1, 2, 3, 4]

// Accessor (returns new array)
const newArr = arr.slice(1, 3);
console.log(newArr); // [2, 3]
console.log(arr); // unchanged [1, 2, 3, 4]

// Iteration (does not mutate)
arr.forEach((x) => console.log(x * 2)); // 2,4,6,8