the empty string的意思|示意

Numeric fields are given the value 0, and string fields have the empty string value.

数值字段被赋以0值，而字符串字段则赋以空字符串值。

Note that I have to check that the attribute is actually present, since when it's absent the contains test would return true (the empty string is contained in all strings).

我必须检查这个属性实际上是否出现，因为当没有这个属性时，contains测试将返回true(所有字符串都包含空字符串)。

Bundle-Version: a version of the form major.minor.micro.qualifier where the first three elements are numeric (defaulting to 0) and qualifier is textual (defaulting to the empty string).

Bundle - Version： major . minor . micro . qualifier形式的版本号，前三个元素是数字(缺省是0)，qualifier则是文本(缺省是空字符串)。

The current design makes it hard to distinguish between an attribute whose value is the empty string and one that isn't present at all.

当前设计很难区分值为空字符串的属性和值根本不存在的属性。

Both of these methods return an empty string if the attribute doesn't exist.

如果属性不存在，那么这两种方法都将返回空字符串。

Recursively, a word is reducible if any of its children are reducible. As a base case, you can consider the empty string reducible.

只要一个单词的孩子还可以缩减，那这个单词本身就亏缩减。你可以认为空字符串是可以缩减的，这样来作为一个基准条件。