変数["名前"]と書く配列を連想配列と呼ぶ(某書籍より)
source <?php $var["data1"] = "連想配列\$var[\"data1\"]の値はdata1です"; print $var["data1"]; print "<br>\n"; print($var["data1"]); print("<br>\n"); echo $var["data1"]; echo "<br>\n"; echo($var["data1"]); echo("<br>\n"); ?>