"; echo gettype($score);//输出：double echo "
"; echo gettype($age);//输出：integer echo "
"; echo gettype($words);//输出：array echo "
"; var_dump(USERNAME);//输出：string(4) "root" echo "
"; var_dump($score);//输出：float(67) echo "
"; var_dump($age);//输出：int(20) echo "
"; var_dump($words);/*输出：array(5) { [0]=> int(2) [1]=> int(4) [2]=> int(6) [3]=> int(8) [4]=> int(10) } */ ?>