Why 7 / 2 = 3.0?

Question

//I think it's a sololearn mistake

double x = 7 / 2;
System.out.println(x);

//ouput 3.0
https://code.sololearn.com/c6uEc1cWs7VT/?ref=app

Answer 1

//try running this...

public class Program
{
public static void main(String[] args) {
double x = 7.0 / 2;
// OR double x = 7 / 2.0;
// OR this double x = (double) 7 / 2; // Casting
System.out.print(x);
}
}

Answer 2

it's not an error, it's just the way the compiler treats how operation should be done.

like in your case, we had

double x = 7/2;

okay x is double so we'll have our answer in Decimal points, fine!

But what about the values are they in double or int?
int, right?

so the compiler compiles this like

2 | 7 | 3
6
------------
1

only 3 is returned to x, however x is double so for the formality, the compiler keeps ".0" at the end of 3.

try making one of the values as double like so...
double x = 7.0 / 2;

or

double x = 7 / 2.0;

Answer 3

7 and 2 are treated as integers.
change 7 to 7.0 or 2 to 2.0 to get a double division.

Answer 4

Thanks!

Answer 5

When you work with variables:
int a = 7, b = 2;

you would not be able to apply the previous tricks, then you would need to use type casting, if you want the result in doubles:
double x = (double) a / b;
//x = 3.5

Answer 6

7and 3 is type of integer so you need type casting you will cast 7 to 7.0
and 3 to 3.0 it will return 3.5

Answer 7

Oh thanks!

Answer 8

The java compiler sees your 7 and 2 as integers and it only converts them to double types after they have been calculated as integers.
This means 7/2 will give 3.
And then the fact that you are assigning the answer to a double variable doesn't actually happen until the whole division.

Which means in
double x= 7/2
The value of x now is actually 3.0 and not 3.5 as you would have expected

Answer 9

Thank you