CODE EXAMPLE FOR PHP

php string literal

sprintf('a %s string with placeholder %s %s %s', $var, ...$array); 
// n additional variables can be passed to sprintf function, or can be passed in an array using the spread opperator in PHP 8.2+

Double Quotes:
"variable {$var} is inline, inside double quotes"

Single Quotes:
'Variable is appended using dots ' . $var . ' to the string.'; 

Newdoc Syntax:
$str = <<<'STR'
Variable is $var
STR;

Heredoc Syntax:
$str = <<<STR
Variable is $var
STR;