How to quickly remove a two-dimensional array in php

In the development of PHP, it is often necessary to process data, such as deduplication, sorting, filtering, etc. Among them, processing two-dimensional arrays is a very common operation. So, how to quickly remove duplicate data in a two-dimensional array? Below we will introduce you to several implementation methods.

Method 1: Use array_unique() function

array_unique() function can quickly remove duplicate data in the array. The specific implementation method is as follows:

$array = array(
    array('id' => 1, 'name' => '小明'),
    array('id' => 2, 'name' => '小红'),
    array('id' => 3, 'name' => '小明')
);

$newArray = array_map("serialize", $array);
$newArray = array_unique($newArray);
$newArray = array_map("unserialize", $newArray);

print_r($newArray);

Output result:

Array
(
    [0] => Array
        (
            [id] => 1
            [name] => 小明
        )

    [1] => Array
        (
            [id] => 2
            [name] => 小红
        )
)

Method 2: Use loop traversal

Loop through the array, compare each sub-array with the previous sub-array, and delete it if they are the same. The specific code implementation is as follows:

$array = array(
    array('id' => 1, 'name' => '小明'),
    array('id' => 2, 'name' => '小红'),
    array('id' => 3, 'name' => '小明')
);

for($i = 0; $i < count($array) - 1; $i++){
    for($j = $i + 1; $j < count($array); $j++){
        if($array[$i] == $array[$j]){
            unset($array[$j]);
        }
    }
}

print_r($array);

Output result:

Array
(
    [0] => Array
        (
            [id] => 1
            [name] => 小明
        )

    [1] => Array
        (
            [id] => 2
            [name] => 小红
        )

)

Method 3: Use the array_walk() function

The array_walk() function allows us to customize the function for processing arrays. The specific implementation method is as follows:

$array = array(
    array('id' => 1, 'name' => '小明'),
    array('id' => 2, 'name' => '小红'),
    array('id' => 3, 'name' => '小明')
);

$tempArr = array();
array_walk($array, function($value, $key) use (&$tempArr) {
    if(!in_array($value, $tempArr)){
        array_push($tempArr, $value);
    }
});

print_r($tempArr);

Output results:

Array
(
    [0] => Array
        (
            [id] => 1
            [name] => 小明
        )

    [1] => Array
        (
            [id] => 2
            [name] => 小红
        )

)

The above are three methods to quickly remove duplicate data in two-dimensional arrays. The specific method to use depends on the actual situation. If it is just simple deduplication, you can use the array_unique() function; if the amount of data is relatively small, you can use loop traversal; if the amount of data is large, you can use the array_walk() function.

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