<?php
$class1 = array("haruki","kaoru","hideto");
$class2 = array("yuki","yuka","manami");
$students = array($class1,$class2);
?>
<?php //連想配列
$result = array(
"japanese" => 80,
"math" => 75,
"science" => 90,
"history" => 85,
"english" => 80
);
?>
<?php
$result["japanese"] = 80;
$result["math"] = 75;
$result["science"] = 90;
$result["history"] = 85;
$result["english"] = 80;
$result ["math"] = 85; //mathの点数を上書き
$result ["music"] = 90; //musicの点数を追加
var_dump($result); //確認
?>