Perl removes leading and trailing blanks

This article mainly introduces Perl delete leading and trailing blanks (remove left and right spaces, white space characters), this article gives a number of methods to achieve this requirement, the need for friends can refer to the following

In other programming languages, Functions LTrim and RTrim are used to remove spaces and tabs from the beginning and end of a string, respectively. Some also provide the function trim to remove whitespace characters at both ends of the string. Perl does not have these functions because simple regular expression substitutions can do this (although I'm sure Cpan has a lot of modules to implement these functions). In fact it was so simple that it became a prominent subject in the Parkinson's trivial theorem.

Left finishing

LTrim or Lstrip remove white-space characters from the left side of the string:

The code is as follows:

$str =~ s/^s+//;

Start with a string to match one or more white-space characters (s+) and replace them with empty characters.

Right Finishing

RTrim or Rstrip remove white-space characters from the right of the string:

The code is as follows:

$str =~ s/s+$//;

Matches one or more white-space characters (s+) until the end of the string ($) and replaces it with a null character.

Finishing both ends

Trim deletes whitespace characters at both ends of the string:

The code is as follows:

$str =~ s/^s+|s+$//g

The above two regular expressions are connected with or marked |, and the last increment is/g to perform the substitution operation globally (repeatedly).

Encapsulated in function

If you don't want to see these structures in your code, you can add them in your code:

The code is as follows:

Sub LTrim {My $s = shift; $s =~-s/^s+//; return $s};

Sub RTrim {My $s = shift; $s =~-s/s+$//; return $s};

Sub Trim {my $s = shift; $s =~ s/^s+|s+$//g, return $s};

When used like this:

The code is as follows:

My $z = "abc";

printf "<%S>