java - s 在 Java 中占用 3 个字节吗？当: String s = "abc"; Java

Question

如果我用 Java 写这个:

String s = "abc";  

难道s在内存中只占3个字节吗？
如果为真，JVM如何找到String对象的结尾？
这会占用更多内存字节吗？

Answer 1

它需要超过 3 个字节，请继续阅读 this page 的完整解释

For reasons we'll explore below, the minimum memory usage of a Java String (in the Hotspot Java 6 VM) is generally as follows:

Minimum String memory usage (bytes) = 8 * (int) ((((no chars) * 2) + 45) / 8)

Or, put another way:

• multiply the number of characters of the String by two;
• add 38;
• if the result is not a multiple of 8, round up to the next multiple of 8;
• the result is generally the minimum number of bytes taken up on the heap by the String.

This page来自同一网站还详细介绍了使用不同于 String

的类来节省内存的方法