如果/ Else三元运营商发布空白其他声明

Question

Usually I can get away with using something like:

$a = ($condition)? array(1,2,3) : '';

But now I have a method that accepts a multidimensional array and I must pass or not pass one of the arrays conditionally.

$this->mymethod(
    'myarrays'=> array(
        array('key' => 'lang_code'),
        array('key' => 'lang_description'),
        array('key' => 'lang_direction'),
        ($mycondition==true)? array('key' => 'lang_export') : ),
    )
);

Basically, the issue is with the last array passed. And more specifically the ELSE statement in the ternary If operator. It seems that I can't pass simply a blank space after the : and I can't pass anything else like FALSE or '' (empty string), because later on in the code the foreach that runs through this array gives errors.

My question is: How to pass a parameter to a function/method based on a condition?

Answer 1

Use:

$mycondition? array('key' => 'lang_export') : null

Now, you could simply run it through array_filter(..) , to remove that NULL element.

Answer 2

array_filter(array(
    array('key' => 'lang_code'),
    array('key' => 'lang_description'),
    array('key' => 'lang_direction'),
    $mycondition ? array('key' => 'lang_export') : null),
));

This will remove the null

Answer 3

Aim for readability, not for how can you type less. The ternary operator is great because in certain cases it increases readability. This is certainly not that case.

Be nice to the people reading your code later, including yourself.

Here is an example (comments are the thoughts of the future reader):

//OK, so here we have an array
$array = array(
    array('key' => 'lang_code'),
    array('key' => 'lang_description'),
    array('key' => 'lang_direction'),
);

//So the array can have one more element based on this condition
if ($mycondition) {
     $array[] = array('key' => 'lang_export');
}

//And then we pass this array to the method
$this->mymethod(array('myarrays' => $array));

You are free to use variables and don't have to write all your code in one statement (well, I must admit I thought that was cool earlier).

Answer 4

You could evaluate the condition before the function call, eg with a helper-function:

function evaluate_condition (array $mandatory, array $optional, $condition) {
    if (true === $condition) {
        $mandatory[] = $optional;
    }
    return $mandatory;
}

$this->mymethod(
    'myarrays'=> $this->evaluate_condition(
        array(
            array('key' => 'lang_code'),
            array('key' => 'lang_description'),
            array('key' => 'lang_direction')
        ),
        array('key' => 'lang_export'),
        $mycondition
    )
);