jAVASCRIPT CHALLENGE QUESTION, CAN NOT FIGURE OUT THE OUTPUT

Question

hI EXPETTS
COULD ANYONE EXPLAIN WHY FOLLOW OUTPUT IS 4? APPRCIATE
var a = [9,5,3];
for(var i=1;i<3;i++){
a[0]%=a[i];
a[0]+=a[2];
}
document.write(a[0]);

Answer 1

a[0]=9 now joining for loop. a[0]=9%a[1]=4 then a[0]=a[0]+a[2] ..current value of a[0]=4 so a[0] becomes 4+3=7. agian i value increase to 2 .since 2 is less than 3.it enters for loop.so a[0]=7%a[2]=1 again a[0]=a[0]+a[2]=1+3=4 ..again i increase to 3.but the condition becomes false so it doesn't go inside the for loop so it exits the loop printing current value which is 4.Sorry for bad English.but I hope you get general idea.

Answer 2

i don't know if i'm wrong but i think answer should be 4
a = [9,5,3]

var i= 1
a[0] = 9%5= 4
a[0] = 4+3 = 7

var i = 2
a[0] = 7%3 = 1
a[0] = 1+3 = 4

so a[0] should be 4

Answer 3

thanks so much, it's very clear now