java - Java中的Double到底是什么意思？

Question

我对 Java 非常陌生，只是想确认一下 Double 是什么？它类似于 Float 还是 Int？任何帮助，将不胜感激。我有时也会看到大写的Double，有时会看到小写的double。如果有人能澄清这意味着什么，那就太好了!

Answer 1

Double是一个包装类，

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.

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.

检查每个数据类型及其范围:Java's Primitive Data Types .

---

重要提示:如果您考虑使用 double 值，您需要在使用前重新考虑。 Java Traps: double