要使用PHP的is_array()函数检查一个变量是否为数组，只需将该变量作为参数传递给函数
<?php
$variable1 = array("apple", "banana", "cherry");
$variable2 = "This is a string";
if (is_array($variable1)) {
echo "Variable 1 is an array.";
} else {
echo "Variable 1 is not an array.";
}
if (is_array($variable2)) {
echo "Variable 2 is an array.";
} else {
echo "Variable 2 is not an array.";
}
?>
在这个例子中，$variable1是一个数组，所以输出结果是"Variable 1 is an array.“。而$variable2是一个字符串，所以输出结果是"Variable 2 is not an array.”。
