What are the differences between using single and double quotes when working with PHP strings?

The main difference between using single and double quotes in PHP strings is that variables and escape sequences are not interpreted within single quotes, whereas they are within double quotes. When using single quotes, the string is treated as a literal value, while double quotes allow for variable interpolation. To solve this issue, use double quotes when you need to include variables or escape sequences within your string. If you do not need variable interpolation, single quotes can be used to improve performance and readability. 

$name = "John";
// Using double quotes for variable interpolation
echo "Hello, $name!";
// Output: Hello, John!

// Using single quotes for a literal value
echo 'Hello, $name!';
// Output: Hello, $name!

Keywords

PHP strings single quotes double quotes concatenation

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