Array Map Filter Reduce

Code

const users = [
  { name: "Alice", age: 30, active: true },
  { name: "Bob", age: 17, active: false },
  { name: "Carol", age: 25, active: true },
];

const names = users.map(u => u.name);
const adults = users.filter(u => u.age >= 18);
const totalAge = users.reduce((sum, u) => sum + u.age, 0);

const carol = users.find(u => u.name === "Carol");
const hasMinor = users.some(u => u.age < 18);
const allActive = users.every(u => u.active);

Explanation

Demonstrates the core functional array methods: map transforms each element, filter selects matching elements, and reduce accumulates a single value. find returns the first match, while some and every test whether elements satisfy a condition. These methods chain together naturally for declarative data processing.

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