2-add-Even-Fibonacci-Num.js

/* Each new term in the Fibonacci sequence is generated by adding the previous
 two terms. By starting with 1 and 2, the first 10 terms will be:
 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
 By considering the terms in the Fibonacci sequence whose values do not exceed
 four million, find the sum of the even-valued terms.

n-th Fib Num =	    0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	...

Actual Fib Num =	0	1	1	2	3	5	8	13	21	34	55	89	144	233	377	...

The final solution to this is - The result of all even numbered Fibonacci numbers less than 4M: 4613732
https://www.mathblog.dk/project-euler-problem-2/

BUT my ans in SOL-2 is different, as I am initiation i, j with 0 and 1.

 */

// SOL-1
addEvenFibNum_1 = num => {

    var i = 1,
        j = 2,
        sum = 2;

    while (j < 4000000) {
        var k = j;
        j += i; // Updating j to take up the next Fibonacci Sequence Number by adding its previous number with its current value
        i = k; // Updating i to take up the next consecutive number (which is the previous value of j)


        if ((j % 2) === 0) {
            sum += j;
        }
    }
    return sum;
}

console.log('Total Sum of even numbered Fibonacci sequence less that 4 million is :' + addEvenFibNum_1(4000000));

// SOL-2 - I gnerally follow this initialization value always
addEvenFibNum_2 = num => {

    var i = 0,
        j = 1,
        fib = 1;
        evenSum = 1;

    while (j < 4000000) {
        fib = i + j;
        j = fib; // Updating j to take up the next Fibonacci Sequence Number by adding its previous number with its current value
        i = fib - i; // Updating i to take up the next consecutive number (which is the previous value of j)


        if ((j % 2) === 0) {
            evenSum += j;
        }
    }
    return evenSum;
}


console.log('Total Sum of even numbered Fibonacci sequence less that 4 million is :' + addEvenFibNum_2(4000000));