PHP Associative Arrays

pivopen pivopen
May 2, 2025 - 17:47
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In PHP, associative arrays are arrays that use named keys (strings) instead of numerical indexes to store values. They're similar to dictionaries or hash maps in other languages.

Basic Syntax

$person = array( "first_name" => "John", "last_name" => "Doe", "age" => 30 );

Or using the short array syntax (PHP 5.4+):

$person = [ "first_name" => "John", "last_name" => "Doe", "age" => 30 ];

Accessing Values

echo $person["first_name"]; // Outputs: John

Adding or Updating Elements

$person["gender"] = "male"; // Adds a new key-value pair $person["age"] = 31; // Updates the existing value

Looping Through Associative Arrays

foreach ($person as $key => $value) { echo "$key: $value<br>"; }

Checking if a Key Exists

if (array_key_exists("age", $person)) { echo "Age is set."; }

Removing an Element

unset($person["age"]);