Page 148 - Beginning PHP 5.3

Part II: Learning the Language
To manipulate the pointer and access the elements that it points to, use the following functions:

Function Description

current() Returns the value of the current element pointed to by the pointer, without
changing the pointer position.

key() Returns the index of the current element pointed to by the pointer, without
changing the pointer position.
next() Moves the pointer forward to the next element, and returns that element’s value.

prev() Moves the pointer backward to the previous element, and returns that element’s value.
end() Moves the pointer to the last element in the array, and returns that element’s value.
reset() Moves the pointer to the first element in the array, and returns that element’s value.

Each of these functions takes just one argument — the array — and returns the required element ’ s value
or index, or false if an element couldn ’ t be found (for example, if you use next() when the pointer is
at the end of the array, or you use current() on an empty array).

Here ’ s an example script that uses each of these functions. You can see the result in Figure 6-2 .
< !DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Strict//EN”
“http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd” >
< html xmlns=”http://www.w3.org/1999/xhtml” xml:lang=”en” lang=”en” >
< head >
< title > Stepping Through an Array < /title >
< link rel=”stylesheet” type=”text/css” href=”common.css” / >
< /head >
< body >
< h1 > Stepping Through an Array < /h1 >

< ?php
$authors = array( “Steinbeck”, “Kafka”, “Tolkien”, “Dickens” );

echo “ < p > The array: “ . print_r( $authors, true ) . “ < /p > ”;
echo “ < p > The current element is: “ . current( $authors ) . “. < /p > ”;
echo “ < p > The next element is: “ . next( $authors ) . “. < /p > ”;
echo “ < p > ...and its index is: “ . key( $authors ) . “. < /p > ”;
echo “ < p > The next element is: “ . next( $authors ) . “. < /p > ”;
echo “ < p > The previous element is: “ . prev( $authors ) . “. < /p > ”;
echo “ < p > The first element is: “ . reset( $authors ) . “. < /p > ”;
echo “ < p > The last element is: “ . end( $authors ) . “. < /p > ”;
echo “ < p > The previous element is: “ . prev( $authors ) . “. < /p > ”;

? >
< /body >
< /html >
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