修改PHP中的多维数组，将键替换为值[duplicate]

Question

This question already has an answer here:

• How to swap keys with values in array? 6 answers

How would you modify the following code using only a foreach loop by replacing the keys as the values? For examples the salad, chicken, and pancakes keys would the values instead.

$meals = array(
    'Lunch' => array(
            'salad' => 'italian',
            'salad2' => 'ranch',
            'salad3' => 'sesame',
            'salad4' => 'bluecheese'
        ), 

    'Dinner' => array(
            'chicken' => 'grilled',
            'chicken2' => 'baked',
            'chicken3' => 'steamed',
            'chicken4' => 'fried',
            'chicken5' => 'broiled'
        ), 

    'Breakfast' => array(
        'pancakes' => 'blueberry',
        'pancakes2' => 'cherry',
        'pancakes3' => 'strawberry',
        'pancakes4' => 'lemon'
        )
);

$newkey = array();

foreach($meals as $key => $value) {
    unset($value);
    // foreach ($)...
}


print_r($meals);

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Answer 1

Edit

If you're unable to use array_flip(), then you'll need to do two loops: one for each meal, and one for each meal option.

Example:

foreach ($meals as $meal => $mealOptions)
{
    $revisedMealOptions = array();

    foreach ($mealOptions as $originalKey => $newKey)
    {
        $revisedMealOptions[$newKey] = $originalKey;
    }

    $meals[$meal] = $revisedMealOptions;
}

Original Answer

It's not entirely clear what you're after. If all you want is to turn:

'Lunch' => array(
    'salad' => 'italian'
);

into

'Lunch' => array(
    'italian' => 'salad'
);

use array_flip().

Example:

$meals['Lunch'] = array_flip($meals['Lunch']);

See http://php.net/manual/en/function.array-flip.php.