Remove leading, trailing and double spaces from a given string.
This task often occurs when you need to clean the user input, such as from web forms, where leading or trailing spaces in, for example, names, are most likely user mistakes and should be removed.
Removing double and multiple spaces between words can be solved by using substitution:
my $string = 'Hello, World!';
$string ~~ s:g/\s+/ /;
Don’t forget to make the substitution global with the :g adverb to find all the occurrences of repeated spaces.
Leading and trailing spaces can be removed with the trimroutine:
my $string = 'Hello, World! ';
say trim($string);
The trim routine exists as a self-standing function, as shown in the previous example, as well as a method of the Str class, so it can be called on a variable or on a string:
say $string.trim;
say ' Hello, World! '.trim;
There are also two routines, trim-leading and trim-trailing, which remove either only leading or only trailing spaces.
say '¡' ~ ' Hi '.trim-leading; # ¡Hi␣␣
say ' Hi '.trim-trailing ~ '!'; # ␣␣Hi!