Complementing what my colleagues have commented on that there are no differences between double and single quotes, I explain the following:
It is recommended to use one of the two types of quotes and be
recurrent in your code with it. If possible, do not use both
for example) or vice versa will be very difficult:
Detect what a comment is and what it is not. Quickly observe the
variables in the code in order to debug it Determine where the term ends
code of one language to start the other
In short, code maintenance will be complex, the code will be a bit illegible and also likely to generate more errors when executing it.
A didactic example is the following:
<?php echo "<script>alert('Hola')</script>"; ?>
How would you do to execute the previous statement if you both put them in double quotes? It would be a bit complicated.
var input = '<input type="text" name="prueba" id="prueba" >';