Arrays are divided into two categories in PHP: numeric index arrays and associative arrays. The numeric index array is the same as the array in C language. The subscripts are 0, 1, 2... and the associative array subscripts may be of any type, similar to hash, map and other structures in other languages.
The following introduces three methods of traversing associative arrays in PHP:
<?php $sports = array( 'football' => 'good', 'swimming' => 'very well', 'running' => 'not good' ); foreach ($sports as $key => $value) { echo $key.": ".$value."<br />"; } ?>
Program running result:
football: good swimming: very well running: not good
<?php $sports = array( 'football' => 'good', 'swimming' => 'very well', 'running' => 'not good' ); while ($elem = each($sports)) { echo $elem['key'].": ".$elem['value']."<br />"; } ?>
Program running result: Program running result:
football: good swimming: very well running: not good
<?php $sports = array( 'football' => 'good', 'swimming' => 'very well', 'running' => 'not good' ); while (list($key, $value) = each($sports)) { echo $key.": ".$value."<br />"; } ?>
Program running result:
football: good swimming: very well running: not good