How to remove a column from php array

In PHP, array is a very common data structure that allows us to store data in an ordered collection. Usually, we use arrays to store some relevant data, such as attributes of a product or information about a person, etc.

Sometimes, we need to delete a column of data in an array, either because we no longer need that particular column, or because we need to rearrange the data. Whatever the reason, PHP provides some simple methods to help us deal with arrays easily.

This article will introduce some methods that allow you to easily delete a column of data in an array.

1. Use the unset() function

The unset() function is a powerful function in PHP that can help us delete any non-array values, array keys and array elements .

We can use the unset() function to delete a column of data in the array, as shown below:

// 定义一个数组
$myArray = array(
    array("name" => "John", "age" => 37, "sex" => "male"),
    array("name" => "Lisa", "age" => 25, "sex" => "female"),
    array("name" => "David", "age" => 42, "sex" => "male")
);

// 删除sex列
foreach($myArray as &$value) {
    unset($value["sex"]);
}

// 输出结果
print_r($myArray);

In the above example, we use the unset() function to delete a column of data in the array. sex" column. We use a foreach loop to iterate through each element in the array and use the unset() function to delete the corresponding column.

2. Using the array_filter() function

The array_filter() function is another practical function in PHP that can help us filter arrays.

We can use the array_filter() function in conjunction with the array_map() function to delete a column of data in the array, as shown below:

// 定义一个数组
$myArray = array(
    array("name" => "John", "age" => 37, "sex" => "male"),
    array("name" => "Lisa", "age" => 25, "sex" => "female"),
    array("name" => "David", "age" => 42, "sex" => "male")
);

// 删除sex列
$myArray = array_map(function($value) {
    unset($value["sex"]);
    return $value;
}, $myArray);

// 输出结果
print_r($myArray);

In the above example, we use the array_map() function to iterate over each element in the array and use an anonymous function to delete the corresponding column. We store the results in a new array and replace the original array with the returned results.

3. Using the array_reduce() function

The array_reduce() function is another practical function in PHP that can help us operate on arrays recursively.

We can use the array_reduce() function in combination with a custom function to delete a column of data in the array, as shown below:

// 定义一个自定义函数
function removeColumn($carry, $item) {
    unset($item["sex"]);
    $carry[] = $item;
    return $carry;
}

// 定义一个数组
$myArray = array(
    array("name" => "John", "age" => 37, "sex" => "male"),
    array("name" => "Lisa", "age" => 25, "sex" => "female"),
    array("name" => "David", "age" => 42, "sex" => "male")
);

// 删除sex列
$myArray = array_reduce($myArray, "removeColumn");

// 输出结果
print_r($myArray);

In the above example, we defined a custom Function removeColumn(), used to delete the "sex" column. We use the array_reduce() function to iterate through each element in the array, and the removeColumn() function to delete the corresponding column. We store the results in a new array and replace the original array with the returned results.

Summary

The above are three common ways to delete a column of data from a PHP array. Each method has its advantages, disadvantages and applicable scenarios. In actual development, please choose the appropriate method according to your own needs and data structure.

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