Something like this but generalized
let arr = [6, 5, 4, 3];
let i = 0, j = 0;
let result = [];
result.push(arr[0]+arr[1],
arr[2]+arr[3]);
console.log(result
Ignoring last element if array has odd number of elements:
function f(arr) {
let result = [];
for (let i=0; i<arr.length; i++) {
if (i % 2==0 && i<arr.length-1) {
result.push(arr[i] + arr[i+1]);
i++;
}
};
return result;
}
let arr = [6, 5, 4, 3];
console.log(f(arr));
console.log(f([1, 2, 3, 4, 5, 6, 7]));