Ruby addict looking for PHP subexpressions in strings

Question

Assume color = "orange";

Ruby:

puts("My favorite color is #{color.downcase() + 'ish'} -- at least for now.");

PHP:

print("My favorite color is {strtolower( $color ) + 'ish'} -- at least for now.");

The PHP version does not work like I would like it to. I'm not looking for any language wars, I just want to know if anyone knows of a way to get PHP to be more like Ruby in this specific regard.

Can anyone help a Ruby addict adjust to his routine visits to PHP-land? Is there an 'act-like-ruby' module somewhere out there? This is starting to hurt.

Answer 1

You're close, you can embed variables in strings, but not function calls.

I use printf() (and sprintf()) for that, which is a thin wrapper around the C function of the same name:

printf('My favorite color is %sish -- at least for now.', strtolower( $color ));

See that %s in there? That's the placeholder for the string data type that you're passing in as the 2nd argument.

sprintf() works the same way, but it returns the formatted string instead of print'ing it.

The only other options are:

A. Performing the function calls first and assigning the end-result to the variable:

$color = strtolower( $color );
print("My favorite color is {$color}ish -- at least for now.");

B. Using concatenation, which is a little ugly IMO:

print('My favorite color is ' . strtolower( $color ) . 'ish -- at least for now.');

You may have noticed my use of single quotes (aka ticks), and double quotes.

In PHP, literals inside double quotes are parsed for variables, as you see in "A" above.

Literals inside single quotes are not parsed. Because of this, they're faster. You should, as a rule, only use double-quotes around literals when there's a variable to be parsed.

Answer 2

'My favorite color is ' . strtolower( $color ) . 'ish-- at least for now.'

I dont think PHP supports full expressions interpolated into strings. Been a while since I did any PHP though.

Answer 3

Not possible. But if you really insist, you can always create a String class with a fluent interface... but that's crazy :)

Answer 4

You can't call plain functions inside strings like that, but you can coax the parser into doing strange things:

<?php
print "{$a->b()}"; // Works

//Parse error: syntax error, unexpected '(' in Command line code on line 1
print "${time()}";

print "${$a=time()} $a"; // Also works: prints "1234380996"
?>

As long as it sees a valid variable at the start, it'll go ahead and interpolate an entire statement without complaining.

For those who were wondering, yes, this works too...

<?php
print "${$a or print shell_exec('ls')}";
?>

Answer 5

If this is anything goes....

class ColorIsh {
    var $color;

    function __constructor($color) { $this->color = $color; }
    function __get($prop) {
        if ($prop == 'ish') {
            // code here fixing suffix if needed
            return strtolower($this->color) . 'ish';
        }
        return '';
    }
    function __set($prop) {}
}

$color = new ColorIsh("orange");
$str = "My favorite color is $color->ish -- at least for now.";

And the hyper advanced version

class ColorIsh {
    private $color;

    function __constructor($color) {$this->color = $color; }
    function __get($prop) {
        if ($prop == 'color') 
            return $this->color;
        if ($prop == 'ish')
            return isset($this->ish) ? $this->ish : $this->color . 'ish';
        return false;
    }
    function __set($prop, $value) {
        if ($prop == 'color') { $this->color = $value; unset($this->ish); }
        if ($prop == 'ish') { $this->ish = $value; }
    }
}

$color = new ColorIsh('orange');
$color->ish = 'orangish';
print "The color is kinda $color->ish";
$color->color = 'green';
print "The color is kinda $color->ish";

output:
The color is kinda orangish.
The color is kinda greenish.