PHP - concatenate or directly insert variables in string

Question

I am wondering, What is the proper way for inserting PHP variables into a string?

This way:

echo \"Welcome \".$name.\"!\"
         


        

Answer 1

Double-quoted strings are more elegant because you don't have to break up your string every time you need to insert a variable (like you must do with single-quoted strings).

However, if you need to insert the return value of a function, this cannot be inserted into a double-quoted string--even if you surround it with braces!

//syntax error!!
//$s = "Hello {trim($world)}!"

//the only option
$s = "Hello " . trim($world) . "!";