Array_key_exists () Definition and usage
The array_key_exists () function determines whether a specified key exists in an array, returns TRUE if the key exists, or returns false.
Grammar
Array_key_exists (Key,array)
Parameter description
Key required. Specify the key name.
Array required. A specified array of inputs.
Example 1
Copy Code code as follows:
<?php
$a =array ("a" => "Dog", "B" => "Cat");
if (Array_key_exists ("a", $a))
{
echo "Key exists!";
}
Else
{
echo "Key does not exist!";
}
?>
Output:
Key exists!
Example 2
Copy Code code as follows:
<?php
$a =array ("a" => "Dog", "B" => "Cat");
if (Array_key_exists ("C", $a))
{
echo "Key exists!";
}
Else
{
echo "Key does not exist!";
}
?>
Output:
Key does not exist!
Example 2
Copy Code code as follows:
<?php
$a =array ("Dog", Cat);
if (array_key_exists (0, $a))
{
echo "Key exists!";
}
Else
{
echo "Key does not exist!";
}
?>
Output:
Key exists!
