How to omit default values of middle parameters when calling a function?

Question

I have function:

function abc( $name, $city = 'duhok', $age = 30 ){

    echo $name.", ".$city.", ".$age;

}

abc( 'Dilovan', null, 26 ); // output: Dilovan, , 26

And I want to output will:Dilovan, duhok, 26

I want way to use this function without set second argument and the second argument write default value.

abc( 'Dilovan', [what i use here to write defualt value ?], 26 );

I disagree that this is a duplicate of that question. This question asks how to apply *the* default value, given in the parameter list. In this case that would be 'duhok'. (The solution may be the same, but I don't think the question is.) — user2864740, Aug 11 '14 at 06:45
@user2864740 , ok. short answer would be: it's not possible. — sectus, Aug 11 '14 at 06:48
Thanks for answers, @sectus I want way it standard off PHP library. — Dilovan Matini, Aug 11 '14 at 07:07

score 4 · Answer 1 · edited Jun 20 '20 at 09:12

4

Short answer: that's not possible without writing some code.

Solution 1

Add this logic to your function body instead of the declaration; for instance:

function abc($name, $city = null, $age = 30)
{
    $city = $city !== null ? $city : 'duhok';
    // rest of your code
}

Then you can call the function like so:

abc('Dilovan', null, 29);

This will assign the default value if the given $city is null.

Solution 2

You can use Reflection to find out what the default value of a parameter is:

$rf = new ReflectionFunction('abc');
$params = $rf->getParameters();

$default_city = $params[1]->getDefaultValue();

abc('Dilovan', $default_city, 26);

edited Jun 20 '20 at 09:12

Community

1
1

answered Aug 11 '14 at 06:47

Ja͢ck

170,779
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OK that is mean not possible, thanks a lot. – Dilovan Matini Aug 11 '14 at 06:56
Mmmm, why that is not possible in PHP ??? – Dilovan Matini Aug 11 '14 at 07:04
@user3928495 That's how default values are implemented in most languages; it's meant to yield its default value *only* if not passed at all. This is also why the optional parameters are always found at the back of the declaration. – Ja͢ck Aug 11 '14 at 07:08
@user3928495 I've updated my answer to show how one could obtain the default value from any function. – Ja͢ck Aug 11 '14 at 07:11
I will try to use Reflection, Its best idea for this Thank you for helping. – Dilovan Matini Aug 11 '14 at 07:17

score -1 · Answer 2 · answered Aug 11 '14 at 06:45

-1

pass null:

abc( 'Dilovan',null, 26 );

answered Aug 11 '14 at 06:45

serakfalcon

3,501
1
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When I pass null will not print anything – Dilovan Matini Aug 11 '14 at 06:57

baxri · Answer 3 · 2014-08-11T06:53:12.990

-1

Test Here

function abc( $name, $city = null, $age = 30 )
{
    if( $city == null )
    {
        $city = 'duhok';
    }

   echo $name.", ".$city.", ".$age;
}


abc( 'Dilovan', null, 26 );

edited Aug 11 '14 at 06:53

answered Aug 11 '14 at 06:46

baxri

307
1
10

Mark as correct answer please if this code heled you – baxri Aug 11 '14 at 06:52
3

It's not considered polite to coax users into accepting your answer without having had some interaction first. – Ja͢ck Aug 11 '14 at 06:57
Yes, I know this way, but I want to pass thing to print default value of argument It is possible ?? – Dilovan Matini Aug 11 '14 at 07:02
In my opinion you cannot do this in diferent way – baxri Aug 11 '14 at 07:05

score -1 · Answer 4 · answered Aug 11 '14 at 06:47

-1

try this

function abc( $name, $city = 'duhok', $age = 30 )
{
    if($city == null || $city == NULL)
    {
        $city = 'duhok'
    }

   echo $name.", ".$city.", ".$age;
}

answered Aug 11 '14 at 06:47

Satish Sharma

9,547
6
29
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I know this way, but I want to pass thing to print default value of argument – Dilovan Matini Aug 11 '14 at 06:59

How to omit default values of middle parameters when calling a function?

4 Answers4

Solution 1

Solution 2