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PHP array_key_exists implementation method to check whether the key name or index exists in the array, arraykeyexists

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2016-07-06 14:24:451007browse

PHP array_key_exists implementation method to check whether the key name or index exists in the array, arraykeyexists

array_key_exists()

PHP array_key_exists() function is used to check whether the given key name or index exists in the array. If it exists, it returns TRUE, otherwise it returns FALSE.

Grammar:

bool array_key_exists(mixed key, array search) parameter key is the given key name or index, which can be any value that can be used as an array index.

The array_key_exists() function also works on objects.

Example:

<&#63;php
$arr_a = array('id' => 1, 'name' => "admin");
if(array_key_exists('name', $arr_a)){
  echo '键名 name 存在于数组 $arr_a 中';
} else {
  echo '键名 name 不存在于数组 $arr_a 中';
}
&#63;>

The example output results are as follows:

The key name name exists in the array $arr_a. The array_key_exists() function still returns TRUE for array elements whose value is null. To check whether an array element is null, use isset().

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