How to remove empty key values ​​from php array

With the widespread application of PHP, developers need to encounter various problems during the development process. Among them, removing empty array key values ​​is one of the common problems. In this article, we will learn how to use PHP array functions to remove empty array keys quickly and easily.

First of all, we need to understand what an empty array key value is. Empty array key values ​​mean that the elements in the array do not have any value or have a value of NULL, that is, they do not contain any useful information. If we retain these empty key values ​​when using arrays, our data will be inaccurate, thus affecting the correctness and performance of the program.

Next, we will introduce three PHP array functions, all of which can be used to remove empty array key values:

1. array_filter()

array_filter() is one of the very practical array functions in PHP. Its function is to filter the elements in an array.

The basic usage is as follows:

array array_filter ( array $array [, callable $callback [, int $flag = 0 ]] )

Among them, the $array parameter is the array that needs to be filtered, the $callback parameter is an optional callback function, and $flag is an optional flag. Specify the execution status of the callback function.

If we want to remove empty array key values, we can do it in the following way:

$arr = array('foo', 'bar', '', 'test', '', 'hello');
$result = array_filter($arr, 'strlen');

In the above code, we use the array_filter() function and strlen() function to achieve this The function to remove empty array key values. The strlen() function is used to get the length of a string. When the length of the string is greater than 0, it will return TRUE, otherwise, it will return FALSE.

2. array_diff()

array_diff() function is used to calculate the difference set of arrays. It receives multiple arrays as arguments and returns an array representing values ​​that are not in those arrays.

The basic usage is as follows:

array array_diff ( array $array1 , array $array2 [, array $ ... ] )

For example, we can use the following code to remove empty array key values:

$array = array('foo', 'bar', '', 'test', '', 'hello');
$result = array_diff($array, array(''));

In the above code, we use array_diff() Function to implement the function of removing empty array key values. We pass an array containing empty strings as a parameter to the array_diff() function, which removes all empty strings in the array.

3. array_values()

array_values() function returns a new array containing all the values ​​in the array, while resetting all array keys.

The basic usage is as follows:

array array_values ( array $array )

For example, we can use the following code to remove empty array key values:

$array = array('foo', 'bar', '', 'test', '', 'hello');
$array = array_values(array_diff($array, array('')));

In the above code, we first use array_diff( ) function removes all empty strings. Subsequently, the array is reset using the array_values() function. This will result in a new array that does not contain any empty elements. The final result can be stored in the $array variable.

Summary

The above are three common PHP array functions, used to remove empty array key values. We can choose different methods for different business needs. When using these functions, you need to pay attention to the format of the parameters passed so that you can get the correct results. I hope this article was helpful to you and can help you better use PHP arrays.

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