How to get specific key value from array in PHP ?

Last Updated : 04 Jul, 2024

In this article, we will see how to get specific key values from the given array. PHP array is a collection of items that are stored under keys. There are two possible types of keys: strings and integers. For any type of key, there is a common syntax to get a specific value by key — square brackets.

Example:

PHP

<?php  $mixedArr = [     10,     20,     'hello' => 'world',     30, ];  // Get a specific value by index $firstItem = $mixedArr[0]; echo "An item by index 0: {$firstItem}\n";  // Get a specific value by string key $stringItem = $mixedArr['hello']; echo "An item by key 'hello': {$stringItem}\n";  ?>

Output

An item by index 0: 10 An item by key 'hello': world

Example 2: Sometimes we can accidentally try to get a non-existent item from the array. In this case, PHP throws a NOTICE. To avoid the issue, we have to check the key existence before accessing it.

PHP

<?php  $arr = [1, 2, 3];  // Check the key existence with  // the built-in 'isset' function if (isset($arr[10])) {     echo "index 10 value is: {$arr[10]}\n"; } else {     echo "There are no value under the index 10\n"; }  $value = $arr[10] ?? 'unknown';  echo "A value under the index 10: {$value}\n";  ?>

Output

There are no value under the index 10 A value under the index 10: unknown

Example 3: Using array_key_exists Function

The array_key_exists function is another way to check if a specific key exists in an array. This function checks if the given key or index exists in the array. Unlike isset, array_key_exists will return true even if the value associated with the key is null.

PHP

<?php $arr = ['a' => null, 'b' => 2]; // Nikunj Sonigara  // Check the key existence with // the built-in 'array_key_exists' function if (array_key_exists('a', $arr)) {     echo "The key 'a' exists in the array.\n"; } else {     echo "The key 'a' does not exist in the array.\n"; }  if (array_key_exists('c', $arr)) {     echo "The key 'c' exists in the array.\n"; } else {     echo "The key 'c' does not exist in the array.\n"; } ?>

Output

The key 'a' exists in the array. The key 'c' does not exist in the array.

Using isset()

In PHP, isset() checks if a variable is set and not null. To get a specific key's value from an array, use isset() to ensure the key exists before accessing its value, avoiding errors if the key is missing.

Example:

PHP

<?php $array = ["name" => "John", "age" => 25, "country" => "USA"]; $key = "age";  if (isset($array[$key])) {     echo $array[$key]; // Output: 25 } else {     echo "Key is not set"; } ?>

Output

Using array_key_first and array_key_last Functions

The array_key_first function returns the first key of the given array without affecting the internal array pointer, while the array_key_last function returns the last key of the given array.

Example:

PHP

<?php  $mixedArr = [     10,     20,     'hello' => 'world',     30, ];  // Get the first key's value $firstKey = array_key_first($mixedArr); $firstValue = $mixedArr[$firstKey]; echo "First key's value: {$firstValue}\n";  // Get the last key's value $lastKey = array_key_last($mixedArr); $lastValue = $mixedArr[$lastKey]; echo "Last key's value: {$lastValue}\n";  ?>

Output

First key's value: 10 Last key's value: 30

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How to get specific key value from array in PHP ?

Using isset()

Using array_key_first and array_key_last Functions

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