What is the problem in this Fibonacci codes ?

Question

https://code.sololearn.com/WAqc0z7PLwMV/?ref=app

https://code.sololearn.com/WCr25c1tZ9gG/?ref=app

Answer 1

Increments are invalid:

// p+=f (1+1= p=2) & f+=p (1+2=3)

My last fibonacci was 5 or 6 months ago, but this works pretty well btw, maybe there is a best solution, i'm too lazy in this moment sry. :3

// t is a "temporary" variable
var p, f, i, t;
i = 0;
p = 1;
f = 0;
document.write(p + "<br />");
// 1
for (; i <= 10; i++) {
t = p;
p += f;
f = t;
document.write(p + "<br />");
}

Answer 2

Actually p is the previous number , f is the fibnocci number , i is for the loop 10 times