Remove the source code line number using a regular expression,

Remove the source code line number using a regular expression,

Abstract: remove the source code line number with a regular expression, and then learn some common Regular Expression operators. Remove the row number step: first use search-replace, then use regular expression to match the row number, and then replace it with null.

The regular expression is:

^\d+\.

Note:

  
^ Indicates the starting position of the row.

  
\ D + match Digit

  
\. Match separator "."

\<\d+\>

It is used to match the line number with spaces and no delimiters in the future.

Table 1 Regular Expression Operators

Operator	Effect
.	Match any single character.
?	The previous items are optional and can be matched at most once.
*	Matches the previous project that appears zero or multiple times.
+	Match the previous project once or multiple times.
{N}	Precisely match N previous projects.
{N ,}	The previous project matches N or more times.
{N, M}	The previous project matches at least N times, but not more than M times.
-	Indicates that the range is not the first or last in the list or the end point of a range.
^	Matches an empty string at the beginning of a row, or a character that is not in the list range.
$	Matches the null string at the end of the row.
\ B	Matches empty strings on both sides of a word.
\ B	Match the provided Null string Matches the empty string provided it's not at the edge of a word.
\ <	Matches an empty string starting with any word.
\>	Matches an empty string at the end of any word.