JavaScript loop doesn't work (learning JS)

Coming from a PHP background, I’m now learning JS, and I don’t understand why this piece of code doesn’t work:

let i = 0;
let arr = [];

while(i < 8){
  arr[i] = i;
  i++;
}

for(i = 0; arr[i]; i++) {
  console.log("Result:", arr[i]);
}

From my point of view, this code is logic:

1. I declare all my variables
2. I put some random values in the array (just to fill it with something)
3. I want to console.log each element of the array while the condition is true

I know that i equals to 8 after the while loop, but even an "i=0" before the for doesn’t solve the issue (BTW why the i = 0 inside the for initialisation doesn’t set it to 0?)

Can someone explain me what breaks the code?

>Solution :

for loops run until the condition is not true.

The first time around the loop i is 0 so arr[i] is arr[0] which you’ve populated with a 0.

0 is a false value, so the condition is false and the loop ends before the first iteration.

You probably want the condition to be i < arr.length.