How to determine whether a two-digit array is empty in php

In PHP, we can use various methods to check whether a two-dimensional array is empty. Some of the different options are described below.

Method 1: Use the count() function

The easiest way is to use the built-in function count(). This function returns the number of elements in the array. If the array is empty, 0 is returned. Therefore, you can determine whether a two-dimensional array is empty simply by counting the number of array elements.

Sample code:

<?php $myArray = array();
if (count($myArray) == 0) {
  echo "二维数组为空";
} else {
  echo "二维数组非空";
}
?>

Method 2: Traverse the array

You can write a loop that traverses the array and checks whether each element exists to determine whether the two-dimensional array is empty . Using a foreach loop, you can easily iterate over an array.

Sample code:

<?php $myArray = array(array());
$isEmpty = true;
foreach ($myArray as $subArray) {
  if (!empty($subArray)) {
    $isEmpty = false;
    break;
  }
}

if ($isEmpty) {
  echo "二维数组为空";
} else {
  echo "二维数组非空";
}
?>

In the above example, we use a foreach loop to traverse the two-dimensional array. The empty() function is used in the inner loop to check whether each subarray exists.

Method 3: Use the array_filter() function

The array_filter() function can filter the elements in the array and return a new array containing elements that meet the conditions.

Sample code:

<?php $myArray = array( array(), array() );
$newArray = array_filter($myArray);

if (empty($newArray)) {
  echo "二维数组为空";
} else {
  echo "二维数组非空";
}
?>

In the above example, we have used the array_filter() function to filter the elements in the two-dimensional array and store them in a new array. Then, we use the empty() function to check if the new array is empty.

Conclusion

You can use one of the above three methods to check whether a 2D array is empty. Each method has many advantages and disadvantages, so when using them, be sure to choose the one that best suits your situation.

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