Think of shift and unshift as the opposites of push and pop except in the sense that shift and unshift work from the 'left' of an array and push and pop work from the 'right' of the array.

eg: Given the list called @foo:

$foo[0] = 'one'; $foo[1] = 'two'; $foo[2] = 'three';
If I were to shift on @foo I'd get the a scalar (assuming that is what I am declaring) equal to the value "one" and now @list would be renumbered so that index 0 of @foo would now be "two" and index 1 of @foo would be "three". This goes the same for unshift. You can unshift the old value back to @foo by unshift(@foo,"one");.

Now, if I push to an array I am actually appending data to the list. If I pop from the array I am taking away from what I just appended thus shifting and unshifting is to add via a prepending of data or taking away what was just prepended.

_ _ _ _ _ _ _ _ _ _
- Jim
Insert clever comment here...


In reply to Re: What are these? by snafu
in thread What are these? by Anonymous Monk

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.