How to determine if a variable is an array in php

In PHP, there are many ways to determine whether a variable is an array. In this article, I will introduce some of the most common methods.

1. Use the is_array() function

The is_array() function is PHP's built-in function, used to determine whether a variable is an array. Its syntax is very simple, just pass the variable to be judged as a parameter to the function.

Sample code:

$array = array('apple', 'banana', 'orange');
if (is_array($array)) {
    echo '是数组';
} else {
    echo '不是数组';
}

Output:

is an array

2. Use gettype() function combined with is_array() function

The gettype() function is used to get the type of a variable. Combined with the is_array() function, you can determine whether the variable is an array.

Sample code:

$array = array('apple', 'banana', 'orange');
if (gettype($array) == 'array') {
    echo '是数组';
} else {
    echo '不是数组';
}

Output:

is an array

3. Use type casting

in PHP , if you cast a non-array type variable to an array type, if it is indeed an array type, the converted variable will still be an array type; otherwise, the converted variable will become an empty array.

Sample code:

$array = array('apple', 'banana', 'orange');
$not_array = 'abc';

// 将非数组类型的变量强制转换成数组类型
$new_array = (array)$array;
$new_not_array = (array)$not_array;

if (is_array($new_array)) {
    echo '$array是数组';
} else {
    echo '$array不是数组';
}

if (is_array($new_not_array)) {
    echo '$not_array是数组';
} else {
    echo '$not_array不是数组';
}

Output:

$array is an array
$not_array is not an array

4. Use count() function

The count() function is used to get the number of elements in the array. When the variable is not an array, the count() function returns 0.

Sample code:

$array = array('apple', 'banana', 'orange');
$not_array = 'abc';

if (count($array)) {
    echo '$array是数组';
} else {
    echo '$array不是数组';
}

if (count($not_array)) {
    echo '$not_array是数组';
} else {
    echo '$not_array不是数组';
}

Output:

$array is an array
$not_array is not an array

To sum up, the above is to judge a Several common methods to determine whether a variable is an array. Using these methods can determine the type of variables more flexibly, thereby avoiding unnecessary errors.

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