正则表达式属性标题大小写(Lt)

Question

我使用属性Lt来匹配单词开头的大写字母(标题大小写(。

我的正则表达式(regex101.com(只是属性p{Lt}，而我的测试字符串是Title Case。

结果是：没有匹配。性质Ll和Lu给出了正确的结果。这种行为的原因是什么？

Answer 1

p{Lt}只匹配Lt类别中的Unuicode字母：

U+01C5   Dž   Latin Capital Letter D with Small Letter Z with Caron
U+01C8   Lj   Latin Capital Letter L with Small Letter J
U+01CB   Nj   Latin Capital Letter N with Small Letter J
U+01F2   Dz   Latin Capital Letter D with Small Letter Z
U+1F88   ᾈ   Greek Capital Letter Alpha with Psili and Prosgegrammeni
U+1F89   ᾉ   Greek Capital Letter Alpha with Dasia and Prosgegrammeni
U+1F8A   ᾊ   Greek Capital Letter Alpha with Psili and Varia and Prosgegrammeni
U+1F8B   ᾋ   Greek Capital Letter Alpha with Dasia and Varia and Prosgegrammeni
U+1F8C   ᾌ   Greek Capital Letter Alpha with Psili and Oxia and Prosgegrammeni
U+1F8D   ᾍ   Greek Capital Letter Alpha with Dasia and Oxia and Prosgegrammeni
U+1F8E   ᾎ   Greek Capital Letter Alpha with Psili and Perispomeni and Prosgegrammeni
U+1F8F   ᾏ   Greek Capital Letter Alpha with Dasia and Perispomeni and Prosgegrammeni
U+1F98   ᾘ   Greek Capital Letter Eta with Psili and Prosgegrammeni
U+1F99   ᾙ   Greek Capital Letter Eta with Dasia and Prosgegrammeni
U+1F9A   ᾚ   Greek Capital Letter Eta with Psili and Varia and Prosgegrammeni
U+1F9B   ᾛ   Greek Capital Letter Eta with Dasia and Varia and Prosgegrammeni
U+1F9C   ᾜ   Greek Capital Letter Eta with Psili and Oxia and Prosgegrammeni
U+1F9D   ᾝ   Greek Capital Letter Eta with Dasia and Oxia and Prosgegrammeni
U+1F9E   ᾞ   Greek Capital Letter Eta with Psili and Perispomeni and Prosgegrammeni
U+1F9F   ᾟ   Greek Capital Letter Eta with Dasia and Perispomeni and Prosgegrammeni
U+1FA8   ᾨ   Greek Capital Letter Omega with Psili and Prosgegrammeni
U+1FA9   ᾩ   Greek Capital Letter Omega with Dasia and Prosgegrammeni
U+1FAA   ᾪ   Greek Capital Letter Omega with Psili and Varia and Prosgegrammeni
U+1FAB   ᾫ   Greek Capital Letter Omega with Dasia and Varia and Prosgegrammeni
U+1FAC   ᾬ   Greek Capital Letter Omega with Psili and Oxia and Prosgegrammeni
U+1FAD   ᾭ   Greek Capital Letter Omega with Dasia and Oxia and Prosgegrammeni
U+1FAE   ᾮ   Greek Capital Letter Omega with Psili and Perispomeni and Prosgegrammeni
U+1FAF   ᾯ   Greek Capital Letter Omega with Dasia and Perispomeni and Prosgegrammeni
U+1FBC   ᾼ   Greek Capital Letter Alpha with Prosgegrammeni
U+1FCC   ῌ   Greek Capital Letter Eta with Prosgegrammeni
U+1FFC   ῼ   Greek Capital Letter Omega with Prosgegrammeni

请参阅regex演示。

您想要的是bp{Lu}，正则表达式将匹配任何前面没有单词char的大写字母。

请参阅regex演示。

根据你想在什么上下文中计算大写字母，正则表达式也可以看起来像

• (?<!p{L})p{Lu}-大写字母，前面没有任何字母
• (?<!S)p{Lu}-一个大写字母，前面没有非空白字符