Question

I often have to assign large strings to variables. In the source code I preferably want to keep my lines within 80 characters.

Ideally I want to be able to lay these literal strings out on multiple lines.

What I want to avoid is using concatenation, or function calls (e.g. preg_replace()), to join multiple strings together in one. I don’t like the idea that I have to invoke language features in order to improve the style of my code.

Example of something I would like:

    $text = <<<TEXT
Line 1
Line 2
Line 3
TEXT;
    echo($text);

This should output:

Line1Line2Line3

Is this possible?

Answer 1

There are a few options:

1. Just concatenate (preferred)

2. Use array constructs

3. Use sprintf()

Just concatenate:

echo 'long long line1'
    . 'another long line 2'
    . 'the last very long line 3';

What about efficiency?

The above code compiles into the following opcodes (which is what’s run):

5    0  >   CONCAT      ~0      'long+long+line1', 'another+long+line+2'
     1      CONCAT      ~1  ~0, 'the+last+very+long+line+3'
     2      ECHO        ~1

As you can see, it builds the string by concatenating the first two lines, followed by the last line; in the end ~0 is discarded. In terms of memory, the difference is negligible.

This is what a single echo statement would look like:

3    0  >   ECHO                'long+long+line1another+long+line+2the+last+very+long+line+3'

Technically it’s faster because there are no intermediate steps, but in reality you won’t feel that difference at all.

Using array:

echo join('', array(
    'line 1',
    'line 2',
    'line 3',
));

Using sprintf():

echo sprintf('%s%s%s',
    'line 1',
    'line 2',
    'line 3'
);