Tell me how to convert double to int ?

  • Convert. Respect the Russian language. - Nikita G.

4 answers 4

The conversion itself is not complicated:

 double doubleValue = 0.0001; int value = (int) doubleValue;

Those. The instruction in general form looks like this:

 type v1 = (type) v2;

But here, there are pitfalls , namely - the type int contains values ​​in the range from -2147483648 to 2147483647 , while they are integer, i.e. without fractional part. A double contains numbers ranging from 4.9E-324 to 4.9E-324 . Those. during conversion, overflow and / or disregarding the fractional part may occur.

For a more flexible conversion, use the BigDecimal and BigInteger classes.

    If you want to round up or down, use Math.round ()

     double a = 1.8; int b = Math.round(a); // b = 2 
       Double mDouble = 0.25; int mInt = (int)mDouble;

        Rounded in the right direction.

          double dx = 10.787901; double newDouble2 = new BigDecimal(dx).setScale(3, RoundingMode.HALF_EVEN).doubleValue(); int ix = (int)newDouble2; // переводим в int

        UP - rounding towards a higher number for positive numbers and a smaller number for negative ones.
        DOWN - rounding to a smaller number for positive numbers and more for negative ones.
        CEILING - rounding to the larger side for both positive and negative numbers.
        FLOOR - rounding in the direction of smaller and for positive, and for negative numbers.
        HALF_UP - rounding up in the case of a number of 0.5
        HALF_DOWN - rounding down in the case of a number of the form 0.5
        HALF_EVEN - classic rounding

        Link to documentation >>>