Floating-Point Literals in Java Programming

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Floating-point numbers are like real numbers in mathematics,
 for example, 6.12536, -0.00002331

A floating-point literal can be denoted as a decimal point, a fraction part,  
and as an integer. We also add a suffix to the floating point literal as D, d, F or f.  
The type of a floating-point literal defaults to double-precision floating-point.
The following floating-point literals represent double-precision floating-point and floating-point values.

 declaration of floating literals are:

2.0f
2.01d
.3f

 double d1 = 4.0;
    double d2 = 2.14159;
    double d3 = 0.7666;

 public class Main {
  public static void main(String[] argv) {
    double d1 = 4.0;
    double d2 = 2.14159;
    double d3 = 0.7666;

    System.out.println("d1 is " + d1);
    System.out.println("d2 is " + d2);
    System.out.println("d3 is " + d3);
  }