Concatenating strings in PHP (https://youtu.be/sOmHCk-_UaM)

string_concatenation.php

// Code to accompany this video: https://youtu.be/sOmHCk-_UaM

// 1. The concatenation operator
$message = "Hello " . "world";  // $message contains "Hello world"

// 2. The concatenating assignment operator
$title = "Home";
$title .= " | About";  // $title now contains "Home | About"

// 3. Splitting concatenations onto more than one line
$seasons = "Spring" . "Summer" . "Autumn" . "Winter";
$seasons = "Spring"
         . "Summer"
         . "Autumn"
         . "Winter";

// 4. Putting a space either side of the operator:
$sql = "SELECT id FROM " . $table_name;

// 5. Simple variable interpolation
$name = "Dave";
$message = "Hello $name!";  // $message contains "Hello Dave!"

// 6. Variable interpolation with curly braces
$prefix = "wp_";
$sql = "INSERT INTO {$prefix}user";  // $sql contains "INSERT INTO wp_user"

// 7. The sprintf function
$temp = 20;
$city = 'Paris';

echo sprintf("It's %d° in %s", $temp, $city);  // outputs "It's 20° in Paris"

// 8. Joining an array of strings with a loop
$categories = ['news', 'tech', 'humour'];
$text = '';

foreach ($categories as $category) {
   $text .= $category . ',';
}
// $text contains "news,tech,humour,"

// 9. Joining an array with the implode function
$categories = ['news', 'tech', 'humour'];

$text = implode(',', $categories);

// $text contains "news,tech,humour"