PHP ternary inside concatenation with no else?

Question

I want to check if 2 variables are the same and if so, echo a string. Is this possible within a concatenation? And to do it without creating a separate function?

e.g.

$var = 'here is the first part and '. ( $foo == $bar ) ? "the optional middle part" .' and the rest of the string.'

EDIT

Note, I'm looking to see if there is a way to do it without the : ''. A "binary operator" if you will.

you cannot use ternary statement without `:` part. why you don't want to use it? — Marko D, Mar 01 '13 at 17:37
It's superfluous—just looking to shorten things up. And sate my OCD. — Andrew Tibbetts, Mar 01 '13 at 17:38

Antony · Accepted Answer · 2013-03-01T17:40:54.573

12

Don't try to shorten things up too much. You need that : '' in order for things to work.

Use (condition) ? "show when true" : "" to display an optional text depending on the condition. A ternary operator is named that way because it consists of 3 parts.

$var = 'here is the first part and '. (( $foo == $bar ) ? "the optional middle part" : "") .' and the rest of the string.';

edited Mar 01 '13 at 17:40

answered Mar 01 '13 at 17:32

Antony

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well, you were few sec quicker. – Marko D Mar 01 '13 at 17:35
@MarkoD But the OP actually changed the question to say "without the `: ''`". – Antony Mar 01 '13 at 17:36
Thanks. I kinda knew this before I posted but hopefully this will help others avoid years of never finding a definite answer. – Andrew Tibbetts Mar 01 '13 at 17:43
I still wish there was a 'binary operator' for if only. :) – Andrew Tibbetts Mar 01 '13 at 17:46
@AndrewTibbetts If you like "binary operator": `$var = 'here is the first part and '; $foo !== $bar || $var.= "the optional middle part"; $var .=' and the rest of the string.';` This doesn't really shorten things up at all. – Antony Mar 01 '13 at 17:56
My brother had the idea to create a function: `function concatenable_if ($statement, $value) { if ($statement) return $value; else return ''; }` but again, I was looking for something built into php. – Andrew Tibbetts Mar 01 '13 at 20:25

cwallenpoole · Answer 2 · 2013-03-01T17:45:03.180

If the question is "Can I do it without the colon and empty quotes?" The answer is no you cannot. You must have the closing :'' and it is best to use paren's to clarify your desires.

$var = 'here is the first part and '. 
        (( $foo == $bar ) ? "the optional middle part":'') .
       ' and the rest of the string.'

I think the biggest problem here is that you're trying to do things inline. This basically boils down to the same process and does not use an unclosed ternary:

$var = 'here is the first part and ';
if( $foo == $bar ) $var .= "the optional middle part";
$var .= ' and the rest of the string.';

Whereas this is another way to accomplish the same goal without needing to worry about conditionals breaking the string:

$middle = '';
if( $foo == $bar ) $middle = ' the optional middle part and';
$var = sprintf('here is the first part and%s the rest of the string.',$middle);

Now, if you are going to be needlessly clever, I suppose you could do this instead:

$arr = array('here is the first part and',
             '', // array filter will remove this part
             'here is the end');
// TRUE evaluates to the key 1. 
$arr[$foo == $bar] = 'here is the middle and';
$var = implode(' ', array_filter($arr));

score 1 · Answer 3 · answered Mar 15 '13 at 20:34

ternary operator syntex is as follows

(any condition)?"return this when condition return true":"return this when condition return false"

so in your string it should be like this

$var = 'here is the first part and '.( ( $foo == $bar ) ? "the optional middle part":"") .' and the rest of the string.'

which means your conditions is missing else past and operator precedence

PHP ternary inside concatenation with no else?

3 Answers3