| Re: Using count() as an array index [message #178415 is a reply to message #178410] |
Fri, 15 June 2012 21:38   |
Denis McMahon
Messages: 634
Registered: September 2010
Karma:
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Senior Member |
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On Fri, 15 Jun 2012 12:51:59 -0600, Martin Leese wrote:
> I am using PHP version 4.2.3. This is old, but I cannot upgrade.
>
> I came across a strange limitation which is puzzling me. The following
> test program:
>
> <?php
> // This PHP file tests the use of count() as an array index
> $anArray[1] = "This is element one";
> $anArray[2] = "This is element two";
> $anArray[3] = "This is the last element";
> //
> echo "$anArray[count($anArray)]\n";
> ?>
>
> produces the error message:
> Parse error: parse error, unexpected T_ENCAPSED_AND_WHITESPACE,
> expecting ']' in CountTest.php on line 7
> Why is using count() as an array index not allowed?
What's not allowed is using a function call as part of a variable
translation inside a string.
> This is no big deal as the work around is trivial; just replace the last
> line with:
>
> $lastIndex = count($anArray);
> echo "$anArray[$lastIndex]\n";
Note that by default, array indexes start at 0.
<?php
$arr = array("first","middle","last");
$len = count($arr);
echo "element {$len} is {$arr[$len]}\n";
?>
Generates output:
============
PHP Notice: Undefined offset: 3 in /home/denis/programming/php/
arrcountfail.php on line 4
element 3 is
============
Rgds
Denis McMahon
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