配列の長さを調べるcount()関数

使い方はcount(配列名)

source

<?php
$myArray[0] = "井上";
$myArray[1] = "柴田";
$myArray[2] = "山口";
$myArray[3] = "清水";
$myArray[4] = "田中";
echo count($myArray);
?>