Question

I’m extremely new to Java and just wanted to confirm what Double is? Is it similar to Float or Int? Any help would be appreciated. I also sometimes see the uppercase Double and other times the lower case double. If someone could clarify what this means that’d be great!

Answer 1

Double is a wrapper class,

The Double class wraps a value of the
primitive type double in an object. An
object of type Double contains a
single field whose type is double.

In addition, this class provides
several methods for converting a
double to a String and a String to a
double, as well as other constants and
methods useful when dealing with a
double.

The double data type,

The double data type is a
double-precision 64-bit IEEE 754
floating point. Its range of values is
4.94065645841246544e-324d to 1.79769313486231570e+308d (positive or negative).
For decimal values, this data type is
generally the default choice. As
mentioned above, this data type should
never be used for precise values, such
as currency.

Check each datatype with their ranges : Java’s Primitive Data Types.

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Important Note : If you’r thinking to use double for precise values, you need to re-think before using it. Java Traps: double