<?php

$a1='abcdef';

echo count($a1);

echo "------";

$a2 = array(array('a',10,20));

echo count($a2);

echo "-----";

$a3 = array(10=>'aa',12=>'cccc');

$a3[] = 'bbb';

var_dump($a3);

?>

/**

输出：

1------1-----

/Users/aaa/Documents/testdemo/test/a.php:10:

array (size=3)

  10 => string 'aa' (length=2)

  12 => string 'cccc' (length=4)

  13 => string 'bbb' (length=3)

  **/