CODEWITHSUNDEEP
phpfunction
tfont
tfont

Reputation: 11233

PHP - Default function arguments

Should empty function arguments be set to NULL or FALSE?

As example follows:

function test1($a = FALSE, $b = FALSE)
{
    if ($b)
    {
        // ... (some awesome code here)
    }

    //.. (more awesome code)
}

test1(0);

OR

function test2($a = NULL, $b = NULL)
{
    if ($b !== NULL)
    {
        // ... (some awesome code here)
    }

    //.. (more awesome code)
}

test2(0);

Note; Also something to consider - while using $a === NULL. One could also use '!empty()' depending if the below code requires empty values or not.

Which is a better design and why?

Upvotes: 0

Views: 77

Answers (3)

Federkun
Federkun

Reputation: 36934

Logically a NULL value should treat as something that doesn't exist. FALSE instead has some semantic value, even if you can consider it as an empty value.

So, use FALSE for an answer to yes or no, NULL as no answer. If your argument is an option like $enable_this it can be a boolean value, and you may want check if it's true with

if ($var)

Instead if you can optionally pass something as an argument, by default it can be NULL, and then you can check if it's really there with 

if($var !== null)

You should use empty only if you want test it to empty value. Cannot $var be an empty string, an empty array, "0" or 0?

Upvotes: 2

Ranhot
Ranhot

Reputation: 334

You could also do it like this:

function test1($a = FALSE, $b = FALSE) {
  if ($b===false) {
    // ... (process default val-false)
  }else{
    //.. (process supplied value)
  }
}

Upvotes: 0

Ijas Ahamed N
Ijas Ahamed N

Reputation: 6110

Use this

function test($a = NULL, $b = NULL)
{
    if ($b !== NULL)
    {
        // ... (some awesome code here)
    }

    //.. (more awesome code)
}

test(0);

Dont use if(!empty($b)), if($b!=NULL) and if(!is_null($b)) because $b=false && $b=0 will fail in this case

Upvotes: 2

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