這個正則表達式的含義

Question

有沒有人可以告訴我這個正則表達式標識是什麼：(?![^&;]+;)(?!<[^<>]*)和(?![^<>]*>)(?![^&;]+;)。

謝謝。

Answer 1

第一招：

二

" 
(?!   # Assert that it is impossible to match the regex below starting at this position (negative lookahead) 
    [^&;]  # Match a single character NOT present in the list 「&;」 
     +   # Between one and unlimited times, as many times as possible, giving back as needed (greedy) 
    ;   # Match the character 「;」 literally 
) 
(?!   # Assert that it is impossible to match the regex below starting at this position (negative lookahead) 
    <   # Match the character 「<」 literally 
    [^<>]  # Match a single character NOT present in the list 「<>」 
     *   # Between zero and unlimited times, as many times as possible, giving back as needed (greedy) 
) 
" 

之一：

" 
(?!   # Assert that it is impossible to match the regex below starting at this position (negative lookahead) 
    [^<>]  # Match a single character NOT present in the list 「<>」 
     *   # Between zero and unlimited times, as many times as possible, giving back as needed (greedy) 
    >   # Match the character 「>」 literally 
) 
(?!   # Assert that it is impossible to match the regex below starting at this position (negative lookahead) 
    [^&;]  # Match a single character NOT present in the list 「&;」 
     +   # Between one and unlimited times, as many times as possible, giving back as needed (greedy) 
    ;   # Match the character 「;」 literally 
) 
" 

注意，這兩個表情並沒有真正捕獲的所有東西，但他們可能是用來精確定位字符串中的位置。沒有任何上下文很難準確地說出它們在哪裏使用。