Problem 2: Even Fibonacci Numbers

Problem 2: Even Fibonacci Numbers

//https://www.freecodecamp.org/learn/coding-interview-prep/project-euler/problem-2-even-fibonacci-numbers

function fiboEvenSum(n) {
  // write a fibo sequence generator
  let fiboArr = [1,2]
  for(let i=0; i < n; i++){
    fiboArr.push(fiboArr[i] + fiboArr[i+1])

  }
  console.log(fiboArr)

  let runningTotal = 0;
  for(let j = 0; j < fiboArr.length;j++){
    if(fiboArr[j] % 2 == 0 && fiboArr[j] <= n){
      console.log(fiboArr[j])
      runningTotal = runningTotal + fiboArr[j]
    }
  }
  // test and track even numbers
  return runningTotal;
}

console.log(fiboEvenSum(10))

Seems to give the correct answer but crashing the browser tab. ?

Spoiler warning: my solution

arr[arr.length - 1] and arr[arr.length - 2] represent the last and second to last numbers in the array

function fiboEvenSum(n) {
  let sum = 0
  let arr = [1, 2]
  while (arr[arr.length - 1] <= n) {
    if(arr[arr.length - 1] % 2 === 0) {
      sum += arr[arr.length - 1]
    }
    arr.push(arr[arr.length - 1] + arr[arr.length - 2])
  }
return sum;
}

@mabolen thanks for the spoiler alert! I haven't peeked yet, gonna tackle this later :)

function fiboEvenSum(n) {
  let sum = 0
  let arr = [1, 2]
  let currentFibo = arr[arr.length - 1];

  while (currentFibo <= n) {
  currentFibo = arr[arr.length - 1];
  let previousFibo = arr[arr.length -2];
    if(currentFibo % 2 === 0) {
      sum += currentFibo
    }
    arr.push(currentFibo + previousFibo)
  }
return sum;
} 

Refactored Marshall's solution to use some nicer variable names.

// This is the refactored version of the original solution we worked on during the first office hours. 

function fiboEvenSum(n) {
  // write a fibo sequence generator
  let fiboArr = [1,2]
  for(let i=0; (fiboArr[i] + fiboArr[i+1]) <= n; i++){
    fiboArr.push(fiboArr[i] + fiboArr[i+1])
  }
  console.log(fiboArr)

  let runningTotal = 0;
  for(let j = 0; j < fiboArr.length;j++){
    if(fiboArr[j] % 2 == 0 && fiboArr[j] <= n){
      console.log(fiboArr[j])
      runningTotal = runningTotal + fiboArr[j]
    }
  }
  // test and track even numbers
  return runningTotal;
}

console.log(fiboEvenSum(10))