JSFiddle - React, Tailwind, and code Playground

by brigand

JavaScript

const arr = [33, 21, 19, 4, 11, 44, 18, 12, 9];

const target = 20;

const has_pair = (arr, target) => {
  const seen = new Set();
  return arr.some((item) => {
  	if (seen.has(target - item)) {
    	return true;
    } else {
    	seen.add(item);
    }
  });
};

console.log(has_pair(arr, target));