array_diff -计算数组的差值

http://php.net/manual/en/function.array-diff.php

数组$array1，数组$array2[，数组$…]) 将array1与一个或多个其他数组进行比较，并返回array1中没有出现在任何其他数组中的值。

array_diff -计算数组的差值

http://php.net/manual/en/function.array-diff.php

数组$array1，数组$array2[，数组$…]) 将array1与一个或多个其他数组进行比较，并返回array1中没有出现在任何其他数组中的值。

使用php函数array_diff(array1, array2);

它将返回数组之间的差值。如果是空的，那么它们相等。

例子:

$array1 = array(
    'a' => 'value1',

    'b' => 'value2',

    'c' => 'value3'
 );

$array2 = array(
    'a' => 'value1',

    'b' => 'value2',

    'c' => 'value4'
 );

$diff = array_diff(array1, array2);

var_dump($diff); 

//it will print array = (0 => ['c'] => 'value4' ) 

示例2:

$array1 = array(
    'a' => 'value1',

    'b' => 'value2',

    'c' => 'value3',
 );

$array2 = array(
    'a' => 'value1',

    'b' => 'value2',

    'c' => 'value3',
 );

$diff = array_diff(array1, array2);

var_dump($diff); 

//it will print empty; 

如果你想检查数组的键和值是否严格相等(===)，你可以使用下面的函数:

function array_eq($a, $b) {
    // If the objects are not arrays or differ in their size, they cannot be equal
    if (!is_array($a) || !is_array($b) || count($a) !== count($b)) {
        return false;
    }
    // If the arrays of keys are not strictly equal (after sorting),
    // the original arrays are not strictly equal either
    $a_keys = array_keys($a);
    $b_keys = array_keys($b);
    array_multisort($a_keys);
    array_multisort($b_keys);
    if ($a_keys !== $b_keys) {
        return false;
    }
    // Comparing values
    foreach ($a_keys as $key) {
        $a_value = $a[$key];
        $b_value = $b[$key];
        // Either the objects are strictly equal or they are arrays
        // which are equal according to our definition. Otherwise they
        // are different.
        if ($a_value !== $b_value && !array_eq($a_value, $b_value)) {
            return false;
        }
    }
    return true;
}

如果你想生成一份详细的报告，你可以使用这样的东西:

function deepCompare(Array $a, Array $b, string $parentAKey, string $parentBKey, bool $compareInverted = true, bool $compareValues = true, string $log = '')
{
    foreach ($a as $aKey => $aValue) {
        $fullAKey = implode('.', [$parentAKey, $aKey]);
        $fullBKey = implode('.', [$parentBKey, $aKey]);
        if (! isset($b[$aKey])) {
            $log .= "⍰ {$fullAKey} has no equivalent {$fullBKey}\n";
        } else {
            $bValue = $b[$aKey];
            if (is_array($aValue)) {
                $log = deepCompare($aValue, $bValue, $fullAKey, $fullBKey, false, $compareValues, $log);
            } else {
              if ($compareValues) {
                  if ($aValue != $bValue) {
                      $log .= "≠ {$fullAKey} value differs from {$fullBKey}\n";
                  }
              }
            }
        }
    }
    if ($compareInverted) {
        $log = deepCompare($b, $a, $parentBKey, $parentAKey, false, false, $log);
    }
    return $log;
}

下面是一个例子:

$november = [
  'site1' => [
    'id' => 15,
    'name' => 'Brazil',
    'extendedHours' => 454,
  ],
  'site2' => [
    'id' => 43,
    'name' => 'Portugal',
    'extendedHours' => 448,
  ],
  'site3' => [
    'id' => 49,
    'name' => 'Spain',
    'extendedHours' => 0,
  ],  
  'totalExtendedHours' => 902,
];

$december = [
  'site1' => [
    'id' => 15,
    'name' => 'Brazil',
    'extendedHours' => 498,
  ],
  'site2' => [
    'id' => 43,
    'name' => 'Portugal',
    'extendedHours' => 409,
    'extraRequests' => 6,
  ],
  'totalExtendedHours' => 907,
  'totalExtraRequests' => 6,
];

echo deepCompare(
    $november,    -- origin array
    $december,    -- target array
    'Nov2022',    -- descriptive name of origin array
    'Dec2022',    -- descriptive name of target array
    true,         -- should also compare arrays in reverse order?
    true          -- should care about array values? (false = names only)
);

这个例子将输出:

≠ Nov2022.site1.extendedHours value differs from Dec2022.site1.extendedHours
≠ Nov2022.site2.extendedHours value differs from Dec2022.site2.extendedHours
⍰ Nov2022.site3 has no equivalent Dec2022.site3
≠ Nov2022.totalExtendedHours value differs from Dec2022.totalExtendedHours
⍰ Dec2022.site2.extraRequests has no equivalent Nov2022.site2.extraRequests
⍰ Dec2022.totalExtraRequests has no equivalent Nov2022.totalExtraRequests

我希望这能帮助到一些人。

比较两个数组是否相等的正确方法是使用严格相等(===)，这是递归比较。现有的答案无法递归地对任意数组(具有任意深度和顺序的数组，包含顺序数组和关联数组的混合)进行排序，因此无法处理任意数组的比较。顺序数组是具有顺序键(0,1,2,3…)的关联数组，而关联数组没有顺序键。

要对这些任意数组排序，我们必须:

向下遍历没有更多子数组的叶节点 通过序列化顺序数组，然后排序它们(以消除必须使用自定义比较器的需要) 按键对关联数组排序

下面的代码实现了上述解决方案。欢迎对代码进行改进。

function recur_sort( &$array ) {
    foreach ( $array as &$value ) {
       if ( is_array( $value ) ) recur_sort( $value );
    }

    if ( is_sequential_array( $array ) ) {
        $array = array_map( function( $el ) { return json_encode( $el ); }, $array  );
        sort( $array, SORT_STRING );
        $array = array_map( function( $el ) { return json_decode( $el, true ); }, $array  );
        return;
    } else {
        return ksort( $array );
    }
}

function is_sequential_array(Array &$a) {
    $n = count($a);
    for($i=0; $i<$n; $i++) {
        if(!array_key_exists($i, $a)) {
            return false;
        }
    }
    return true;
}

示例(在PHPUnit中):

//A stricter and recursive assertEqualsCanonicalizing
public function assertSameCanonicalizing( $expected, $actual ) {
    recur_sort( $expected );
    recur_sort( $actual );
    $this->assertSame( $expected, $actual );
}