Ternary statement without middle expression

Question

How to replace this :

if( $this->getInfo() ){
   $value = $this->getInfo();
}else{
   $value = $this->getAnotherInfo();
}

This would be nicer solution :

$value = $this->getInfo() ? $this->getInfo() : $this->getAnotherInfo();

But we repeat $this->getInfo().

first, assign the result of `$this->getInfo()` to the variable, then work with this variable. Otherwise you can't escape double calling of this method. — Deadooshka, May 24 '14 at 16:25
possible duplicate of [?: operator PHP](http://stackoverflow.com/questions/1993409/operator-php) — Artjom B., May 24 '14 at 16:28
But in this expr `$var = fn() ? : 1;` fn() called once. Tested. — Deadooshka, May 24 '14 at 16:43

score 1 · Accepted Answer · edited May 24 '14 at 16:17

1

Here is the fun:

$value = $this->getInfo() ? : $this->getAnotherInfo();

edited May 24 '14 at 16:17

Giacomo1968

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answered May 24 '14 at 16:04

jody_lognoul

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Did you correctly answer your own question? Looks like a syntax error to me. – Popnoodles May 24 '14 at 16:07
2

@Popnoodles: No, that's valid syntax. It's called the shorthand ternary syntax. See the [documentation](http://www.php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary): "*Since PHP 5.3, it is possible to leave out the middle part of the ternary operator. Expression `expr1 ?: expr3` returns `expr1` if `expr1` evaluates to `TRUE`, and `expr3` otherwise.*". – Amal Murali May 24 '14 at 16:13
Ok thanks, I've never seen it before. So he answered his own question. – Popnoodles May 24 '14 at 16:13

score 0 · Answer 2 · answered May 24 '14 at 16:10

If it bothers you having to repeat the expression you could write a function that returns the first truthy value.

$value = which ($this->getInfo(), $this->getAnotherInfo());

function which () { 
    if (func_num_args()<1) return false;
    foreach (func_get_args() as $s) if ($s) return $s;
    return false;
}

Tom Fenech · Answer 3 · 2014-05-24T16:19:42.687

A nasty option would be this:

if (!($value = $this->getInfo())) $value = $this->getOtherInfo();

If the assignment returns false assign the other value.

But aside from this looking disgusting, it is still repetitive, albeit in a different way.

As of PHP 5.3, you can leave out the middle part of the ternary operator and avoid the repetition:

$value = $this->getInfo() ? : $this->getOtherInfo();

Which does what you want.

Ternary statement without middle expression

3 Answers3