Searching Algorithms (linear search, binary search)

const arr = [1, 3, 5, 7, 9];
const target = 5;
const found = arr.some(x => x === target);

Returns boolean vs index
some() differs from indexOf() because: 1) Returns true/false instead of index, 2) Stops at first match like indexOf, 3) Uses linear search internally, 4) Can use complex predicates, 5) More expressive for existence checks, 6) Same O(n) time complexity, 7) Part of functional programming paradigm, 8) Better for simple existence testing.
Uses binary search
Faster execution
Requires sorted array