Why does Java think that the product of all numbers from 10 to 99 is 0?

Question

The following block of codes gives the output as 0.

public class HelloWorld{

    public static void main(String []args){
        int product = 1;
        fo         


        

Answer 1

Somewhere in the middle you get 0 as the product. So, your entire product will be 0.

In your case :

for (int i = 10; i < 99; i++) {
    if (product < Integer.MAX_VALUE)
        System.out.println(product);
    product *= i;
}
// System.out.println(product);

System.out.println(-2147483648 * EvenValueOfi); // --> this is the culprit (Credits : Kocko's answer )

O/P :
1
10
110
1320
17160
240240
3603600
57657600
980179200
463356416
213837312
-18221056
-382642176
171806720
-343412736
348028928
110788608
-1414463488
464191488
112459776
-1033633792
-944242688
793247744
-385875968
150994944
838860800
-704643072
402653184
2013265920
-805306368
-1342177280  --> Multiplying this and the current value of `i` will also give -2147483648 (INT overflow)
-2147483648  --> Multiplying this and the current value of `i` will also give -2147483648 (INT overflow)

-2147483648  ->  Multiplying this and the current value of 'i' will give 0 (INT overflow)
0
0
0

Every time you multiply the current value of i with the number you get 0 as output.