如何找到文本中匹配的单词的索引？

Question

我正在提取与此正则表达式匹配的单词索引。它使用正则表达式匹配文本中所有必需的单词，但它也匹配正则表达式左侧的空格。它不是限制左侧文本中的匹配字符串，而是使用 限制匹配字符串的右侧\b正则表达式：(price|rs)?\s*(\d+[\s\d.]*\s*?(pkg|k|m|(?:la(?:c|kh|k)|crore|cr)s?|l)\b\.?)输入文本：    This should matchprice  5.6 lacincluding price(i.e  price 5.6 lac) and rs 56 m. including rs (i.e rs 56 k  rs 56 m) .It will match normally if there is no price or rs written for example or                   56 k or   8.8 crs.   are  correct matching but its should bound the matched string from left side as well just like its not matching sapce after end of the matched string.It should not match the spaces left of 8.5 in this      8.5 lac ould not match eitherrs 6 lac asas there is no spaces before 5.6How can I modify above regex to bound the matched word in the left side as well? 

Answer 1

您可以将 移动\s*到可选的非捕获组中：

(?:\b(price|rs)\s*)?(\d+[\s\d.]*\s*?(pkg|k|m|(?:la(?:c|kh|k)|crore|cr)s?|l)\b\.?)
^^^^^^^^^^^^^^^^^^^^

查看正则表达式演示

该(?:\b(price|rs)\s*)?模式会匹配字边界，随后与price或rs所遵循与0+空格字符，整个图案将曾经尝试，并且图案是可选的，由于?改性剂（图案的整个序列可以匹配1或0次）