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
– Deadooshka, Commented May 24, 2014 at 16:25
But in this expr $var = fn() ? : 1; fn() called once. Tested. — Deadooshka
– Deadooshka, Commented May 24, 2014 at 16:43

Giacomo1968 · Accepted Answer · 2014-05-24 16:17:24Z

1

Here is the fun:

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

edited May 24, 2014 at 16:17

Giacomo1968

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answered May 24, 2014 at 16:04

jody_lognoul

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3 Comments

Popnoodles Over a year ago

Did you correctly answer your own question? Looks like a syntax error to me.

Amal Over a year ago

@Popnoodles: No, that's valid syntax. It's called the shorthand ternary syntax. See the documentation: "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.".

Popnoodles Over a year ago

Ok thanks, I've never seen it before. So he answered his own question.

Popnoodles · Accepted Answer · 2014-05-24 16:10:45Z

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 · Accepted Answer · 2014-05-24 16:19:42Z

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.

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