PitifulProgrammer:

Yeah, map is one of my favorite bits. It's a simple way to build one list given another list. You need only give it a chunk of code to call for each element in the list, and whatever it returns is the content of the new list.

my @list = (1, 2, 3, 4, 5);

# makes list: 2, 4, 6, 8, 10
my @even_numbers = map { $_*2   } @list;

# makes list: 1, 4, 9, 16, 25
my @squares      = map { $_*$_  } @list;

# makes list: 1, 1, 2, 2, 3, 3, 4, 4, 5, 5
my @repeated_list= map { $_, $_ } @list;

@list = qw(foo bar baz);

# makes list 'foo', 'bar', 'baz'
my @single_quoted = map { "'$_'" } @list;

[download]

...roboticus

When your only tool is a hammer, all problems look like your thumb.

In reply to Re^9: comparing contents of two arrays and output differences by roboticus
in thread comparing contents of two arrays and output differences by PitifulProgrammer

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.