为什么这个 while 循环会一直循环下去？

Question

I have tried looking at documentation and could not figure it out. My while loop does not stop and prints "ya" forever. What am I doing wrong?

var ya = 1;
Formitivegrades = [100, 95, 100, 85, 100]
Formitiaveav1 = Formitivegrades[0] + Formitivegrades[1] + Formitivegrades[3] + Formitivegrades[4] + Formitivegrades[2]
Formitiaveav2 = Formitiaveav1 / 5

sumgrades = [100]
sumav1 = ya + sumgrades[0]
sumav2 = sumav1 / 2

averge = .4 * Formitiaveav2 + .6 * sumav2

while(averge < 95){
    console.log(ya)
    ya++;
}

console.log(averge)

Answer 1

Don't think of the equal sign = as an equality that is guaranteed forever, the way it is in mathematics. In programming it is a one-time assignment. An assignment statement gives a variable a new value at that moment in time only. If they change values afterwards the equality can be broken.

If ya is updated that does not cause sumav1 to be recalculated. Nor does sumav2 change whenever sumav1 changes, nor avrge when sumav2 changes. averge keeps the same value forever unless you explicitly update it.

To that end, you need to recompute all of the variables each time you change ya . That way averge can eventually reach 95 and cause the loop to end.

while(averge < 95){
    console.log(ya)
    ya++;

    sumav1 = ya + sumgrades[0]
    sumav2 = sumav1 / 2
    averge = .4 * Formitiaveav2 + .6 * sumav2
}