Question

I need avoid round number when casting a float to string, I need the number is exactly the same.

In this moment if I make this:

String value =  String.valueOf(1234567.99);

The the value = 1234568.0 ,so I need the value = 1234567.99 after casting.

Answer 1

1234567.99 can’t be exactly represented as a float. The nearest float is actually equal to 1234568.

If you want more precision, you can use a double: 1234567.99d will do what you expect.

You can run this simple test to check it (it is in Java but easily transposable on android by replacing the println):

public static void main(String[] args) {
    float f = 1234567.99f;
    double d = 1234567.99d;
    System.out.println(new BigDecimal(f));
    System.out.println(new BigDecimal(d));
}

prints:

1234568
1234567.98999999999068677425384521484375

Note: String.valueOf(double) does round the double to another representation, with less decimals, of the same double. In other words, as you see above 1234567.99d can’t be represented as a double and the nearest double is 1234567.98999999999068677425384521484375. But String.valueOf figures it out and uses the first representation of that double (with only 2 decimals) since they are effectively the same double according to the specifications of the language.