Perl | Removing leading and trailing white spaces (trim)

Removing unwanted spaces from a string can be used to store only the required data and to remove the unnecessary trailing spaces. This can be done using trim function in Perl. Trim function uses the regular expression to remove white spaces. It is not a library function but defined by the user whenever required. The types of trim functions are:

  • Left Trim (~ s/^\s+//): Removes extra spaces from leftmost side of the string till the actual text starts. From the leftmost side the string takes 1 or more white spaces (\s+) and replaces it with nothing.
  • Right Trim (~ s/\s+$//): Removes extra spaces from rightmost side of the string till the actual text end is reached. From the rightmost side the string takes 1 or more white spaces (\s+) and replaces it with nothing.
  • Trim (~ s/^\s+|\s+$//): It removes extra space from both sides of the string.

Example: The following code demonstrates the left trim, right trim and trim in Perl:

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# Perl program for removing leading and
# trailing white spaces using trim
  
#!/usr/bin/perl
  
# Original String
$str1 = "     Geeks----";
  
print"The Original String is:\n";
print"${str1}\n\n";
  
# Applying left trim to str1
print"After Lefttrim Str1:\n";
$str1=~ s/^\s+//;
print"${str1}\n\n";
  
# again intializing the 
# value to string
$str1 = "----Geeks     ";
  
# Applying right trim to str1
print"After Righttrim Str1:\n";
$str1=~ s/\s+$//;
print"${str1}\n\n";
  
# again intializing the 
# value to strings
$str1="      Geeks      ";
  
  
# Applying trim to str1
print"After trim Str1:\n";
$str1=~ s/^\s+|\s+$//g;
print"${str1}\n";

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Output:

The Original String is:
     Geeks----

After Lefttrim Str1:
Geeks----

After Righttrim Str1:
----Geeks

After trim Str1:
Geeks


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