What is the difference between single-quoted and double-quoted strings in PHP?

The main differences between single-quoted and double-quoted strings in PHP are:

1. Variable interpolation: Double-quoted strings allow variables to be interpolated directly within the string, while single-quoted strings treat variables literally and do not evaluate them[1][2][3]. For example:

$name = "John";
echo "Hello, $name!"; // Output: Hello, John!
echo 'Hello, $name!'; // Output: Hello, $name!

2. Escape sequences: Double-quoted strings interpret escape sequences like \n for newline, while single-quoted strings treat escape sequences literally[1][2][3]. For example:

echo "Hello\nWorld"; // Output: 
                     //Hello
                     //World
echo 'Hello\nWorld'; // Output: Hello\nWorld

3. Performance: Single-quoted strings are slightly faster than double-quoted strings because PHP doesn't need to parse variables and escape sequences within them[1][2]. However, this difference is negligible in most cases.

4. Escaping quotes: To include a single quote ...