Function array_is_list() in PHP to checks if an array is a list (a sequential, zero-based indexed array)

Current PHP usage

array_is_list() checks whether an array has consecutive integer keys starting at 0. It distinguishes list-shaped arrays from associative or non-consecutive arrays.

$items = ['a', 'b', 'c'];
var_dump(array_is_list($items)); // true

An empty array is also considered a list. The function checks the key structure, not the types of the stored values.

The array_is_list() function in PHP is used to determine if an array is a list. A list is an array with sequential integer keys starting from 0.

Syntax

array_is_list(array $array): bool

The function returns true if the array is a list and false otherwise.

The array_is_list() function is available in PHP 8.1 and later versions only.

Example 1: Simple Indexed Array

$array = [10, 20, 30]; 
$result = array_is_list($array); 
echo $result ? 'True' : 'False';

True

Example 2: Associative Array

$array = ['a' => 1, 'b' => 2]; 
$result = array_is_list($array); 
echo $result ? 'True' : 'False';

False

Example 3: Array with Mixed Keys

$array = [0 => 'apple', 'x' => 'banana', 1 => 'orange']; 
$result = array_is_list($array); 
echo $result ? 'True' : 'False';

False

Example 4: Empty Array

$array = []; 
$result = array_is_list($array); 
echo $result ? 'True' : 'False';

True

Example 5: Non-sequential Indexed Array

$array = [0 => 'apple', 2 => 'banana', 3 => 'orange']; 
$result = array_is_list($array); 
echo $result ? 'True' : 'False';

False

Example 6 : Not starting with 0 as key

$array = [1=>'Green',2=>'Red',3=>'Blue']; // Not starting with 0
$result = array_is_list($array); 
echo $result ? 'True' : 'False';

False

Example 7 : Starting from negative number

$array = [-1=>'Green',0=>'Red',1=>'Blue']; // Not starting from 0 
$result = array_is_list($array); 
echo $result ? 'True' : 'False';

False

Conclusion

The array_is_list() function helps you differentiate between indexed and associative arrays in PHP, making array manipulation more efficient and structured.
To check the variable is array or not
Array REFERENCE

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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