Strings in PHP
Single vs Double Quotes
$name = "Alice";
echo "Hello \$name"; // interpolates
echo 'Hello $name'; // literalConcatenation
$greeting = "Hello" . " " . "World";Heredoc & Nowdoc
$html = <<Title
HTML;Common String Functions
strlen()
strpos()
substr()
str_replace()
explode() / implode()
trim()
strtolower() / strtoupper()