Double with double

　　

A double is a class double that is the underlying data type. The double type is a wrapper class of double, which, after JDK1.5, can be directly assigned to each other, called auto-unpacking and auto-boxing. Looking at your tips, I guess your JDK version was 1.5 ago. If so, you can use the method in double to convert the wrapper class to a basic data type, such as double amount = Rec.getamount (). Doublevalue ();D ouble There are ways to call equals is a method that belongs to a class If you want to compare the value of the size, then use = = but double must first turn into double
As for how to turn, look at the double method.

Double with double