In PHP: If I start a new line while writing a string in my source is it necessary to concatenate the string?

Question

I'm learning PHP and MySQL together from Head First PHP & MySQL and in the book, they often split their long strings (over 80~ characters) and concatenate them, like this:

$variable = "a very long string " .
    "that requires a new line " .
    "and apparently needs to be concatenated.";

I have no issue with this, but what strikes me odd is that whitespace in other languages usually don't need concatenation.

$variable = "you guys probably already know
    that this simply works too.";

I tried this and it worked just fine. Aren't line breaks always interpreted with a space at the end? Even the PHP manual doesn't concatenate in the echo examples if they span over one line.

Should I follow my book's example or what? I can't tell which is more correct or "proper" since both work and the manual even takes a shorter approach. I also would like to know how important is it to keep code under 80 characters in width? I have always been fine with word warp since my monitor is pretty large and I hate my code getting cut short when I have the screen space.

Answer 1

In PHP long strings don't need concatenation but keep in mind that:

    $variable = "you guys probably already know
that this simply works too.";

is the equivalent of

$variable = "you guys probably already know\nthat this simply works too.";

The newline is just the same in these 2 examples (if your system uses \n as a newline - Windows uses \r\n).

So to answer your question, no, you don't have to break large strings in many smaller ones. Doing so is just a matter of preference (which I don't really often see).

Answer 2

The 80 char "limit" is throwback to the old days where terminal screens had an 80 char width. If you ever need to edit something in a narrow width terminal, respecting 80 chars can be helpful. However, if longer than 80 char lines wrapping are causing you headaches in your editor, Don't follow that convention.

When you have a multi-line string as in your second example, the string will be exactly as you type it in your editor. If you have a whole bunch of spaces before your retrun char, those will be in your string var. The only exception to this is if your editor is doing line wrapping, then there is not actually a return char in the string, and it won't show up in the variable.

Answer 3

PHP syntax allows literal line feeds in the strings. Your second example equals this:

you guys probably already know[LF][SPACE][SPACE][SPACE][SPACE]that this simply works too.

where [LF] will be \r\n or \n depending on your editor settings. Those redundant spaces may be an issue or not (not everything is HTML), but it's not the same as concatenating.

Answer 4

There's 3 basic ways of building multiline strings in PHP.

a. building string via concatenation and embedded newlines:

$str = "this is the first line, with a line break\n";
$str .= "this is the second line, but won't have a break";
$str .= "this would've been the 3rd line, but since there's no line break in the previous line..."`

b. multi-line string assignment, with embedded newlines:

$str = "this is the first line, with a line break\n
this is the second line, because of the line break.
this line will actually is actually part of the second line, because of no newline";

c. HEREDOC syntax:

$str = <<<EOL
this is the first line
this is the second line, note the lack of a newline
this is the third line\n
this is actually the fifth line, because the newline previously isn't necessary.
EOL;

Heredocs are generally preferable for building multi-line strings. You don't have to escape quotes within the text, variables are interpolated within them as if it was a regular double-quoted string, and newlines within the text are honored.

Answer 5

No.

1) open quotes
2) write as much as you need, adding spaces, tabs, whatever else
3) close quotes.

If you're using the same quotes within, escape them with \

"Jane said \"It's hot today!\"";

or

'Jane said "It\'s hot today!"';