my@colors=('red', 'cyan', 'yellow', 'blue' );
my @yw_colors = grep  {/yw/}  @colors;
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UPDATE: Add a print statement. And the regex should be /x|y/, i.e. you want to find an x or an y, not x followed by y. Another possible regex that would work would use a character class: /[xy]/

i tried but it doesn't work,slightly i change my code then it works that is

my @yw_colors = grep  {/yw/}  @colors; '
print @yw_colors,$/
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