为什么是'123'数字？(Why does Apache Commons consider '१२३' numeric?)

为什么是'123'数字？(Why does Apache Commons consider '१२३' numeric?)

根据文档 ，字符串'123'是数字。

由于我认为这可能是文档中的错误，我运行测试来验证该语句。 我发现根据Apache Commons它是数字的。

为什么这个String数字？ 那些字符代表什么？

According to Apache Commons Lang's documentation for StringUtils.isNumeric(), the String '१२३' is numeric.

Since I believed this might be a mistake in the documentation, I ran tests to verify the statement. I found that according to Apache Commons it is numeric.

Why is this String numeric? What do those characters represent?

最满意答案

因为“CharSequence只包含Unicode数字”（引用链接的文档 ）。

Character.isDigit所有字符都返回true：

一些包含数字的Unicode字符范围：

'\ u0030'到'\ u0039'，ISO-LATIN-1数字（'0'到'9'） '\ u0660'到'\ u0669'，阿拉伯语 - 印数字 '\ u06F0'到'\ u06F9'，扩展阿拉伯语 - 印度数字 '\ u0966'到'\ u096F'，梵文数字 '\ uFF10'通过'\ uFF19'，全宽数字

许多其他字符范围也包含数字。

१२३是梵文数字：

१是DEVANAGARI DIGIT ONE， \u0967 २是DEVANAGARI DIGIT TWO， \u0968 ३是DEVANAGARI DIGIT三， \u0969

Because that "CharSequence contains only Unicode digits" (quoting your linked documentation).

All of the characters return true for Character.isDigit:

Some Unicode character ranges that contain digits:

'\u0030' through '\u0039', ISO-LATIN-1 digits ('0' through '9') '\u0660' through '\u0669', Arabic-Indic digits '\u06F0' through '\u06F9', Extended Arabic-Indic digits '\u0966' through '\u096F', Devanagari digits '\uFF10' through '\uFF19', Fullwidth digits

Many other character ranges contain digits as well.

१२३ are Devanagari digits:

१ is DEVANAGARI DIGIT ONE, \u0967 २ is DEVANAGARI DIGIT TWO, \u0968 ३ is DEVANAGARI DIGIT THREE, \u0969