How Do You If a Key Is Defined in an Array
Q
How Do You If a Key Is Defined in an Array? - PHP Script Tips - PHP Built-in Functions for Arrays
✍: FYIcenter.com
A
There are two functions can be used to test if a key is defined in an array or not:
- array_key_exists($key, $array) - Returns true if the $key is defined in $array.
- isset($array[$key]) - Returns true if the $key is defined in $array.
Here is a PHP example script:
<?php
$array = array("Zero"=>"PHP", "One"=>"Perl", "Two"=>"Java");
print("Is 'One' defined? ".array_key_exists("One", $array)."\n");
print("Is '1' defined? ".array_key_exists("1", $array)."\n");
print("Is 'Two' defined? ".isset($array["Two"])."\n");
print("Is '2' defined? ".isset($array[2])."\n");
?>
This script will print:
Is 'One' defined? 1 Is '1' defined? Is 'Two' defined? 1 Is '2' defined?
2007-04-20, 5275👍, 0💬
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