HOWTO · PHP

PHP 中對陣列分組

本教程演示瞭如何根據 PHP 中的特定列對多維陣列的元素進行分組。

PHP 沒有任何內建函式可以對陣列進行分組,但可以使用迴圈來實現。

對陣列進行分組有助於按單個屬性對陣列項進行分組。

在 PHP 中使用 foreach 迴圈按特定屬性對陣列進行分組

<?php
$data_array = array(
    array(
        "Name" => "Mark",
        "Gender" => "Male",
        "EmployeeType" => "FullTime"
    ),
    array(
        "Name" => "Monica",
        "Gender" => "Female",
        "EmployeeType" => "FullTime"
    ),
    array(
        "Name" => "John",
        "Gender" => "Male",
        "EmployeeType" => "PartTime"
    ),
    array(
        "Name" => "Michelle",
        "Gender" => "Female",
        "EmployeeType" => "PartTime"
    )
);

$grouped_array = array();
foreach ($data_array as $element) {
    $grouped_array[$element['Gender']][] = $element;
}

$grouped_array1 = array();
foreach ($data_array as $element) {
    $grouped_array1[$element['EmployeeType']][] = $element;
}
echo "Array grouped according to gender: <br>";
print_r($grouped_array);
echo "<br><br>Array grouped according to employee type: <br>";
print_r($grouped_array1);
?>

輸出:

Array grouped according to gender:
Array (
[Male] => Array (
[0] => Array ( [Name] => Mark [Gender] => Male [EmployeeType] => FullTime )
[1] => Array ( [Name] => John [Gender] => Male [EmployeeType] => PartTime ) )
[Female] => Array (
[0] => Array ( [Name] => Monica [Gender] => Female [EmployeeType] => FullTime )
[1] => Array ( [Name] => Michelle [Gender] => Female [EmployeeType] => PartTime ) ) )

Array grouped according to employee type:
Array (
[FullTime] => Array (
[0] => Array ( [Name] => Mark [Gender] => Male [EmployeeType] => FullTime )
[1] => Array ( [Name] => Monica [Gender] => Female [EmployeeType] => FullTime ) )
[PartTime] => Array (
[0] => Array ( [Name] => John [Gender] => Male [EmployeeType] => PartTime )
[1] => Array ( [Name] => Michelle [Gender] => Female [EmployeeType] => PartTime ) ) )

我們將陣列排列成多行。輸出顯示兩個陣列,一個根據 Gender,另一個是 EmployeeType

在 PHP 中使用 group_array() 建立一個可以對給定陣列進行分組的函式

我們可以將上面的程式碼轉換為函式,然後放入值。

<?php
function group_array($property, $data) {
    $grouped_array = array();

    foreach($data as $value) {
        if(array_key_exists($property, $value)){
            $grouped_array[$value[$property]][] = $value;
        }else{
            $grouped_array[""][] = $value;
        }
    }

    return $grouped_array;
}
echo "Array grouped according to gender: <br>";
print_r(group_array("Gender", $data_array));
echo "<br><br>Array grouped according to employee type: <br>";
print_r(group_array("EmployeeType", $data_array));
?>

我們建立一個函式 group_array(),它有兩個引數,一個是屬性或鍵,另一個是陣列。

輸出:

Array grouped according to gender:
Array (
[Male] => Array (
[0] => Array ( [Name] => Mark [Gender] => Male [EmployeeType] => FullTime )
[1] => Array ( [Name] => John [Gender] => Male [EmployeeType] => PartTime ) )
[Female] => Array (
[0] => Array ( [Name] => Monica [Gender] => Female [EmployeeType] => FullTime )
[1] => Array ( [Name] => Michelle [Gender] => Female [EmployeeType] => PartTime ) ) )

Array grouped according to employee type:
Array ( 
[FullTime] => Array (
[0] => Array ( [Name] => Mark [Gender] => Male [EmployeeType] => FullTime )
[1] => Array ( [Name] => Monica [Gender] => Female [EmployeeType] => FullTime ) )
[PartTime] => Array ( 
[0] => Array ( [Name] => John [Gender] => Male [EmployeeType] => PartTime )
[1] => Array ( [Name] => Michelle [Gender] => Female [EmployeeType] => PartTime ) ) )