A value containing a decimal point is assumed to be the 64-bit double, : double « Java Source And Data Type « SCJP

1. SCJP
2. Java Source And Data Type
3. double

unless you append an F or f to indicate the 32-bit float primitive.

public class MainClass {
  public static void main(String[] argv) {
    double f2 = 1.023; // double is assumed
    float d2 = 1.023F; // F or f makes it a float

    System.out.println();
  }
}