How to create an array with key value pairs in PHP?

PHP offers us a special type of array called an Associative Array that allows us to create an array with Key-Value pairs. The syntax for creating an Associative Array is as follows:

Syntax 1: Using array() constructor

$arrayVariable = array(
    key1  => value1,
    key2 => value2,
    key3 => value3,
    ...
    keyN => valueN,
);

Syntax 2: Using shorthand notation

$arrayVariable = [
    key1  => value1,
    key2 => value2,
    key3 => value3,
    ...
    keyN => valueN,
];

Note:

1. The comma after the last Key-Value pair is optional.
2. The Key can be of either integer or string type.
3. The Value can be of any valid type.
4. If the type of Key is other that string or integer, it will be cast to string or integer depending on the type of Key.

Example 1: Using array() constructor

<?php
$websites = array(
    "Facebook" =>
"Facebook, Inc. is an online social media and
 social networking service company.",
    "Twitter" =>
"Twitter is a microblogging and social networking service on
which users post and interact with messages known as tweets.",
    "LinkedIn" =>
"LinkedIn is a business and employment-oriented service
 that operates via websites and mobile apps.");

$websites["Instagram"] = "Instagram is a photo and video-sharing
social networking service owned by Facebook, Inc.";
foreach ($websites as $key => $value) {
    echo "<p>$key: $value <p>";
}
?>

Output:

Example 2: Using shorthand notation

<?php
$websites = [
    "Facebook" =>
"Facebook, Inc. is an online social
    media and social networking service company.",

    "Twitter" => "Twitter is a microblogging and social networking service
    on which users post and interact with messages known as tweets.",

    "LinkedIn" => "LinkedIn is a business and
    employment-oriented service that operates via websites and mobile apps."];

$websites[
    "Instagram"] = "Instagram is a photo and video-sharing
    social networking service owned by Facebook, Inc.";
foreach ($websites as $key => $value) {
    echo "<p>$key: $value <p>";
}
?>

Output: