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

In PHP, you can use some functions and techniques to determine whether a two-dimensional array is empty. This article will introduce several methods to determine whether a two-dimensional array is empty.

Method 1: Use the array_filter() function

The array_filter() function is one of PHP's built-in functions, used to filter elements in an array. If the array is empty, the function will return false. Therefore, we can judge whether the two-dimensional array is empty based on this.

The following is a sample program:

$myArray = array(
  array('name' => 'Peter', 'age' => '26'),
  array('name' => 'Jack', 'age' => '32'),
  array('name' => 'Tom', 'age' => '28')
);

// 使用 array_filter() 函数过滤二维数组
$result = array_filter($myArray);

if ($result) {
  echo "二维数组不为空";
} else {
  echo "二维数组为空";
}

Instructions:

• First declare a two-dimensional array $myArray, which contains three elements;
• Then use the array_filter() function to filter the elements in the $myArray array;
• Use the if statement for judgment.

Method 2: Use the count() function

Another method is to use the count() function, which is used to count the number of elements in the array. If the array has no elements, the function will return 0. Therefore, you can use the count() function to determine whether the two-dimensional array is empty.

The following is an example:

$myArray = array(
  array('name' => 'Peter', 'age' => '26'),
  array('name' => 'Jack', 'age' => '32'),
  array('name' => 'Tom', 'age' => '28')
);

// 使用 count() 函数计算二维数组的长度
$length = count($myArray);

if ($length > 0) {
  echo "二维数组不为空";
} else {
  echo "二维数组为空";
}

Explanation:

• First declares a two-dimensional array $myArray, which contains three elements;
• Then use the count() function to calculate the length of the array;
• Then use the if statement to judge.

Method 3: Use foreach loop

You can also use foreach loop to determine whether the two-dimensional array is empty. This method is relatively simple, just iterate through the array and check whether each of its sub-arrays is empty.

The following is an example:

$myArray = array(
  array('name' => 'Peter', 'age' => '26'),
  array('name' => 'Jack', 'age' => '32'),
  array('name' => 'Tom', 'age' => '28')
);

$isEmpty = true;

foreach ($myArray as $subArray) {
  if (!empty($subArray)) {
    $isEmpty = false;
    break;
  }
}

if ($isEmpty) {
  echo "二维数组为空";
} else {
  echo "二维数组不为空";
}

Explanation:

• First declares a two-dimensional array $myArray, which contains three elements;
• Then use a foreach loop to traverse each element of the array;
• If a sub-array in the array is not empty, set the $isEmpty variable to false and interrupt the loop;
• Finally use The if statement makes a judgment.

Summary

This article introduces three methods to determine whether a two-dimensional array is empty, using the array_filter() function, count() function and foreach loop. These methods are all convenient for determining whether an array is empty, but which method to choose depends on the specific situation. It needs to be selected based on factors such as code structure and execution efficiency.

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