PHP removes null values ​​from two-dimensional array

In PHP development, arrays often need to be processed, and removing null values ​​​​in arrays is a common requirement. This article will introduce how to use PHP language to remove null values ​​​​in a two-dimensional array.

First of all, we need to understand the concept of two-dimensional array. A two-dimensional array is an array composed of a set of arrays. Each array is also called a one-dimensional array. Each one-dimensional array stores multiple elements internally. In PHP, we can use the following method to define a two-dimensional array:

$array = array(
    array("apple", "banana", "", "orange"),
    array("pear", "", "watermelon", "pineapple"),
    array("grape", "lemon", "mango", ""),
);

The above code defines a two-dimensional array containing three one-dimensional arrays. Each one-dimensional array stores several element, which may contain null values. We now need to remove all null values ​​​​in this two-dimensional array. The specific operations are as follows.

1. Use foreach loop to traverse two-dimensional array

We can use foreach loop to traverse two-dimensional array and take out each one-dimensional array for operation. The code is as follows:

foreach($array as $k=>$v){
    //操作每个一维数组
}

In the above code, $array represents the two-dimensional array to be traversed, $k represents the subscript of the one-dimensional array currently traversed, and $v represents the one-dimensional array currently traversed.

2. Use the array_filter function to remove null values ​​in a one-dimensional array

We can use the array_filter function to remove null values ​​in a one-dimensional array. The array_filter function returns a new array with all null values ​​in the original array removed. The code is as follows:

$newArr = array_filter($v);

In the above code, $v represents the one-dimensional array currently traversed, and $newArr represents the new array after removing null values.

3. Assign the new array to the corresponding position in the original array

We need to assign the new array after removing the null values ​​to the corresponding position in the original array to achieve Remove null values ​​from a two-dimensional array. The code is as follows:

$array[$k] = $newArr;

In the above code, $k represents the subscript of the currently traversed one-dimensional array, $newArr represents the new array after removing null values, $array[$k] represents the original two-dimensional array A one-dimensional array of corresponding positions in .

4. Complete code

To sum up, we can write the complete code as follows:

$array = array(
    array("apple", "banana", "", "orange"),
    array("pear", "", "watermelon", "pineapple"),
    array("grape", "lemon", "mango", ""),
);

foreach($array as $k=>$v){
    //去除一维数组中的空值
    $newArr = array_filter($v);
    //将新数组赋值给原数组中的对应位置
    $array[$k] = $newArr;
}

The above code will remove the two-dimensional array NULL value and save the result in the original array. The running results are as follows:

Array
(
    [0] => Array
        (
            [0] => apple
            [1] => banana
            [2] => orange
        )

    [1] => Array
        (
            [0] => pear
            [1] => watermelon
            [2] => pineapple
        )

    [2] => Array
        (
            [0] => grape
            [1] => lemon
            [2] => mango
        )

)

The above is the method of removing null values ​​​​in a two-dimensional array introduced in this article. I hope it will be helpful to everyone.

The above is the detailed content of PHP removes null values ​​from two-dimensional array. For more information, please follow other related articles on the PHP Chinese website!