How to remove null values ​​from array in php

When processing arrays, sometimes we need to remove the null values ​​in order to get more accurate results. The following describes how to operate an array in PHP and remove null values ​​​​from it.

There are many functions in PHP that can operate on arrays, such as unset(), array_filter(), array_values(), etc. The unset() function is used to delete the specified variable, while the array_filter() function can filter elements in the array, and the array_values() function can return all arrays value. These functions can be used to remove null values ​​​​from arrays. Let's take a look at how to use these functions in detail.

Use the unset function to delete null values

unset The function can be used to delete specified elements in an array. We can use foreach to loop through the array and use the unset function to delete null values.

<?php
$arr = array(&#39;aa&#39;, &#39;&#39;, &#39;bb&#39;, null, 0, &#39;cc&#39;);
foreach($arr as $k=>$v){
    if(!$v){
        unset($arr[$k]);
    }
}

By traversing the array, we can delete the null values ​​​​in it. However, it should be noted that after using the unset function, the key names of the array are discontinuous, that is, there will be gaps in the array subscript.

Use the array_filter function to filter empty values

array_filter The function can filter the elements in the array according to the specified rules and return a new array.

<?php
$arr = array(&#39;aa&#39;, &#39;&#39;, &#39;bb&#39;, null, 0, &#39;cc&#39;);
$arr = array_filter($arr,function($v){
    if($v === &#39;&#39; || $v === null || $v === 0){
        return false;
    }else{
        return true;
    }
});
?>

In the above code, we use the array_filter function and pass in the judgment function to judge whether each element of the array is empty. If it is empty, delete it from the array. .

Use the array_values ​​function to re-index the array

array_values The function can remove the key names in the associative array and return an index array.

<?php
$arr = array(&#39;aa&#39;, &#39;&#39;, &#39;bb&#39;, null, 0, &#39;cc&#39;);
$arr = array_filter($arr,function($v){
    if($v === &#39;&#39; || $v === null || $v === 0){
        return false;
    }else{
        return true;
    }
});
$arr = array_values($arr);
?>

In the above code, we use the array_values function to reassign the returned array to $arr to get a new index array. In this way, the operation of removing null values ​​​​in the original array can be achieved.

Summary

The above is how to remove null values ​​​​from an array in PHP. We can delete specified elements by using the unset function, we can also use the array_filter function to filter out non-empty elements, and we can also use the array_values function to re-index the array. Depending on the actual situation, choose different methods to operate the array.

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