float variables initialization java

Question

The following code snippet gave me compiler error at Line 1.

public abstract class xyz
{

    float Gamma = 20.0; //Line 1
    public class Alpha
    {
        v         


        

Answer 1

should be

float density = 20.0f;

Answer 2

As per my understanding, float is used for decimal variables.

No. Numerical literals with fraction parts are treated as doubles by default.

Answer 3

float density = 20.0f;

If you try to assign a decimal number you must place an "f" at the end, otherwise Java will assume you are trying to assign a double .A double would more precisely cover more numbers that you could type in.

Answer 4

In Java by default decimal values are stored as double. But for storing it as a floating point number we explicitly need to declare, like

float varName = 10.0f; or float varName = (float)10.0;

Answer 5

Floating-point literals are considered doubles unless you specify that they're just floats. (Similarly, integer literals are ints unless specified otherwise.) Append the letter f to the number to make it a float:

float density = 20.0f;

The JLS has comprehensive typing rules for literal values. No, you don't have to make the literal a float with f, but then you have to cast it with (float) if you want to fit it in a float variable, since Java won't automatically try to shove a number of one type into a variable with a smaller range.

Answer 6

Per the JLS, §3.10.2, all floating point literals are interepreted as double unless specified as a float.

A floating-point literal is of type float if it is suffixed with an ASCII letter F or f; otherwise its type is double and it can optionally be suffixed with an ASCII letter D or d (§4.2.3).

Change your declaration to:

float density = 20.0f;

In general, consider why you're using float - it has less precision than double, and isn't used nearly as often.