How to delete duplicate elements in a two-dimensional array in PHP? (Pictures + Videos)

This article mainly introduces to you the specific implementation method of PHP to delete duplicate elements in a two-dimensional array!

In the previous article [How to delete duplicate elements in an array in PHP? ] has introduced to you the method of deleting ordinary one-dimensional arrays in PHP. Friends who need it can refer to it first.

Simply put, a two-dimensional array is an array of arrays. You need two indexes to select elements.

Below we will introduce in detail the method of deleting duplicate elements in a two-dimensional array through specific code examples!

<?php
/**
 * PHP删除二维数组中的重复元素
 */

// 对二维数组进行去重复
function more_array_unique($arr)
{
    //先把二维数组中的内层数组的键值记录在在一维数组中
    foreach ($arr[0] as $k => $v) {
        $arr_inner_key[] = $k;
    }
    foreach ($arr as $k => $v) {
        //降维 用implode()也行
        $v = join(",", $v);
        //保留原来的键值 $temp[]即为不保留原来键值
        $temp[$k] = $v;
    }
    //去重：去掉重复的元素
    $temp = array_unique($temp);
    foreach ($temp as $k => $v) {
        //拆分后的重组 如：Array( [0] => 张三 [1] => 18 )
        $a = explode(",", $v);
        //将原来的键与值重新合并
        $arr_after[$k] = array_combine($arr_inner_key, $a);
    }
    return $arr_after;
}

$arr = [
    [&#39;name&#39; => &#39;张三&#39;, &#39;age&#39; => 18],
    [&#39;name&#39; => &#39;Tom&#39;, &#39;age&#39; => 19],
    [&#39;name&#39; => &#39;Tom&#39;, &#39;age&#39; => 19],
    [&#39;name&#39; => &#39;张三&#39;, &#39;age&#39; => 50],
    [&#39;name&#39; => &#39;王小二&#39;, &#39;age&#39; => 30],
];
echo "<pre class="brush:php;toolbar:false">";
print_r(more_array_unique($arr));

In this code, we define a two-dimensional array of $arr, which has two pairs of repeated elements, "Zhang San" and "Tom", but their ages are different.

Everyone should know that the array_unique() function only applies to one-dimensional arrays, so for two-dimensional arrays we need to define a function method ourselves, but the array_unique() function can also be used.

As in the above code example, we defined the more_array_unique method to delete duplicate elements in a two-dimensional array.

Note:

join function is an alias of this function: implode().

array_combine function: means to create an array, using the value of one array as its key name and the value of another array as its value

array_unique function: remove the array Duplicate values ​​in .

Finally accessed through the browser, the result of deleting the duplicate elements of the two-dimensional array is as follows:

As shown in the figure, we use the customized more_array_unique method, Remove completely duplicate elements from a two-dimensional array while retaining useful information.

This article is about the specific method of PHP deleting duplicate elements in a two-dimensional array. I hope it will be helpful to friends in need!

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