PHP：优雅的方式来预测关联数组的子阵列

Question

I have an associative array of arrays. The associative array of arrays does not always contain the same sub-arrays. I would like to loop through a particular sub-array if it exists. Is there a more elegant way to do the following code:

if ( array_key_exists( 'fizzy_drinks', $drinks ) ) {

    foreach ( $drinks['fizzy_drinks'] as $fizzy_drink ) {

        // do something with $fizzy_drink
    }
}

Answer 1

Not really, this is as much elegant as it gets:

if (isset($drinks['fizzy_drinks'])) {
    foreach ( $drinks['fizzy_drinks'] as $fizzy_drink ) {
        // do something with $fizzy_drink
    }
}

If you omit the isset you will get a notice if fizzy_drinks is not set, and a warning if $drinks is not an array.

Answer 2

You might prefer to use is_array :

if(is_array($drinks['fizzy_drinks'])) {
  foreach ($drinks['fizzy_drinks'] as $fizzy_drink) {
    // do something with $fizzy_drink
  }
}

Answer 3

You can use:

if (! empty($drinks['fizzy_drinks']) && is_array($drinks['fizzy_drinks'])) {
    foreach ($drinks['fizzy_drinks'] as $fizzy_drink) {
        // do something with $fizzy_drink
    }
}

no warnings, no notices

Answer 4

Not really. I think your solution is quite elegant, and readable. I would do:

if (array_key_exists('fizzy_drinks', $drinks) && is_array($drinks['fizzy_drinks'])) {
    foreach ($drinks['fizzy_drinks'] as $fizzy_drink ) {
        // do something with $fizzy_drink
    }
}

Always nice to check if the value you try to use foreach on really is an array.