This tutorial will discuss about unique ways to check if an index exists in array in php.
Table Of Contents
Method 1: Using array_key_exists() function
The array_key_exists()
function in PHP accepts an index/key and an array as arguments. It checks if the given array contains the given key or index. If yes, then it returns true, otherwise it returns false.
We can use this to check if a given index is valid or not i.e. it exists in the array or not.
Let’s see the complete example,
<?php $arr = array('for', 'why', 'this', 'here', 'some'); $index = 2; // Check if index is valid in array if (array_key_exists($index, $arr)) { echo "The given Index exists in the array"; } else { echo "The given Index does not exists in the array"; } ?>
Output
The given Index exists in the array
Method 2: Using isset() function
Select element at given index
from the array
i.e. $arr[$index]
, and then pass it to the isset()
function, to check if this is declared or not. If it is set and has any value other then null, then it will return true. This way we can check if an index
is valid or not for an array
.
Frequently Asked:
- Check if Array Contains Duplicates in PHP
- Check if Array Contains All Values of Another Array in PHP
- Check if an Array contains a value in PHP
- Check if array contains value from another array in PHP
Let’s see the complete example,
<?php $arr = array('for', 'why', 'this', 'here', 'some'); $index = 2; // Select the element at given index from array // and check it is set i.e. if index is valid if (isset($arr[$index])) { echo "The given Index exists in the array"; } else { echo "The given Index does not exists in the array"; } ?>
Output
The given Index exists in the array
Summary
We learned two ways to check if an index exists in an array or not.