What goes in double quotes and what goes in single quotes?

[Mr__Mojo_Risin]

I'm learning PHP and I'm confused as to when to use " and when to use '

thanks

[Schwarzwald]

Use double quotes when you might have variables that need to be substituted into the string.

A good example is a database query:

$query = "SELECT * FROM users WHERE id=$id";

Without the double quotes, the $id would not be substituted into the string - it would be ran "as is".

As such, use single quotes when you know that there won't be any variables in your string. I believe these cut down slightly on overhead, as PHP won't take the time to try and substitute variables.

[TomD]

More than you ever wanted to know about PHP strings can be found here .

An example of single quotes would be if you wanted a string to include double quotes without escaping them as in:

$this_string = 'She said, "Hello"';

using double quotes it would have to be:

$this_string = "She said, \"Hello\"";

or as a variable:

$whatwassaid = '"Hello"';

$this_string = "She said, $whatwassaid";

Is that all clear as mud?

[slaya]

cant you just do

$this_string = 'SlaYa OwNz ',$name,' !';
or
$this_string = 'SlaYa OwNz ' . $name . ' !';

[TomD]

$this_string = 'SlaYa OwNz ' . $name . ' !';

would work fine.