数字文字中是否存在任何下划线？

Question

我刚刚阅读了Java7中的增强功能( http://docs.oracle.com/javase/7/docs/technotes/guides/language/underscores-literals.html).在那里,我看到了Underscores Numeric Literals并尝试了Like ....

int i=9_000; 没关系.

但我看到规则,它也允许...

int i=9____________________________________________________________________________________000;

有没有结束Underscores？

Answer 1

没有限制.为什么会这样？另一方面,我看到使用任意数量的下划线的唯一原因是能够做下面的代码中的花哨的东西(由Joshua Bloch创建,如果我没有记错的话):

private static final int BOND =
     0000_____________0000________0000000000000000__000000000000000000+
   00000000_________00000000______000000000000000__0000000000000000000+
  000____000_______000____000_____000_______0000__00______0+
 000______000_____000______000_____________0000___00______0+
0000______0000___0000______0000___________0000_____0_____0+
0000______0000___0000______0000__________0000___________0+
0000______0000___0000______0000_________0000__0000000000+
0000______0000___0000______0000________0000+
 000______000_____000______000________0000+
  000____000_______000____000_______00000+
   00000000_________00000000_______0000000+
     0000_____________0000________000000007;