int a, b, c, d, sum, average;

​

    cout << "Input the 1st number: ";

    cin >> a;

    cout << "Input the 2nd number: ";

    cin >> b;

    cout << "Input the 3rd number: ";

    cin >> c;

    cout << "Input the 4th number: ";

    cin >> d;

​

    sum = a+b+c+d;

    average = sum/4;

​

    cout << "The average is: " << average << endl;

const arr = [2, 4, 5, 6];

​

// Find average function

function fAve(totalVal, arrVal, index, array) {

    const val = totalVal + arrVal;

    if (index === array.lengh -1) {

        return val / array.length;

    }

    return val;

}

​

// Pass function into reduce method

const average = arr.reduce(fAve);

​

console.log(average);

​

​

//node (js file name).