Find if there exists two number in array that have sum equal to target.

findIfSumExists.js

function isThere(arr, t) {
	//Usually Mergesort	n log(n)
  arr.sort((a,b)=> a>b?true:false);
	
	let i = 0, 
		j = arr.length-1,
		x = arr[i], 
		y = arr[j];
	
  // O(n)
	while( x + y !== t) {
		( x + y > t) ? j-- : i++;		
		x = arr[i], y = arr[j];
		if ( i >= j) return false;
	}
	console.log(x,y);
	return true;
}