在|的右侧捕获单词（或）在正则表达式中不在左边

Question

我正在尝试捕获此正则表达式右侧未在左侧捕获的单词。

在下面的代码中，左侧捕获＆＃34; 17英寸＆＃34;在这个字符串中：＆＃34;这个235 / 45R17是一个17英寸的轮胎＆＃34;

(?<=([-.0-9]+(\s)(inches|inch)))|???????

然而，我放在右侧的任何东西，例如简单的+ w都会干扰左侧

我如何告诉RegEx捕获任何单词，除非它是一个数字后跟英寸 - 在这种情况下捕获17和英寸？

Answer 1

描述

((?:(?![0-9.-]+\s*inch(?:es)?).)+)|([0-9.-]+\s*inch(?:es)?)

_{**要更好地查看图像，只需右键单击图像并在新窗口中选择视图}

实施例

现场演示

https://regex101.com/r/fY9jU5/2

示例文字

this 235/45R17 is a 17 inch tyre

样本匹配

• 捕获组1将是与17 inch
不匹配的值
• Capture Group 2将是英寸数

MATCH 1
1.  [0-20]  `this 235/45R17 is a `

MATCH 2
2.  [20-27] `17 inch`

MATCH 3
1.  [27-32] ` tyre`

解释

NODE                     EXPLANATION
----------------------------------------------------------------------
  (                        group and capture to \1:
----------------------------------------------------------------------
    (?:                      group, but do not capture (1 or more
                             times (matching the most amount
                             possible)):
----------------------------------------------------------------------
      (?!                      look ahead to see if there is not:
----------------------------------------------------------------------
        [0-9.-]+                 any character of: '0' to '9', '.',
                                 '-' (1 or more times (matching the
                                 most amount possible))
----------------------------------------------------------------------
        \s*                      whitespace (\n, \r, \t, \f, and " ")
                                 (0 or more times (matching the most
                                 amount possible))
----------------------------------------------------------------------
        inch                     'inch'
----------------------------------------------------------------------
        (?:                      group, but do not capture (optional
                                 (matching the most amount
                                 possible)):
----------------------------------------------------------------------
          es                       'es'
----------------------------------------------------------------------
        )?                       end of grouping
----------------------------------------------------------------------
      )                        end of look-ahead
----------------------------------------------------------------------
      .                        any character except \n
----------------------------------------------------------------------
    )+                       end of grouping
----------------------------------------------------------------------
  )                        end of \1
----------------------------------------------------------------------
 |                        OR
----------------------------------------------------------------------
  (                        group and capture to \2:
----------------------------------------------------------------------
    [0-9.-]+                 any character of: '0' to '9', '.', '-'
                             (1 or more times (matching the most
                             amount possible))
----------------------------------------------------------------------
    \s*                      whitespace (\n, \r, \t, \f, and " ") (0
                             or more times (matching the most amount
                             possible))
----------------------------------------------------------------------
    inch                     'inch'
----------------------------------------------------------------------
    (?:                      group, but do not capture (optional
                             (matching the most amount possible)):
----------------------------------------------------------------------
      es                       'es'
----------------------------------------------------------------------
    )?                       end of grouping
----------------------------------------------------------------------
  )                        end of \2
----------------------------------------------------------------------

Answer 2

首先更换所有不需要的东西更简单，更安全 然后才匹配你要找的东西。

例如在这个javascript示例中：

var str = "this 235/45R17 is a 17 inch tyre of more than 9 inches."; 
var result = str.replace(/\s[\d.\-]+\sinch(?:es)?/gi, "").match(/\-?\d+\.?\d*/gi);

提供结果235,45,17

可能出现负面预测，但最好使用边界\ b。
避免仍然匹配不匹配的数字中第一个数字的问题。

例如：

var result = str.match(/(?:\-?\d+\.?\d*)(?:[a-z]|\b)(?!\s+inch(?:es)?)/gi);

提供结果235,45R,17