How to Call Function inside Array

Question

I will create a json file with PHP with json_encode. I intend to include a function that I will call inside array before I change it to json. Whether calling functions inside an array can be done?

$arrayList = array( 
                array( 
                'uid' => "1234",
                'nilai' => getBoolean (1)));                
function getBoolean ($value) {
    if ($value == 0 ) {
        echo "false";
    } else {
        echo "true";
    }   
}
echo json_encode ($arrayList);

Output json

true[{"uid":"1234","nilai":null}]

What if I want json output like below

[{"uid":"1234","nilai":true}]

So the value of the function (getBoolean) goes into json not outside. Thanks

Answer 1

PHP uses an applicative order evaluation strategy so getBoolean(1) will be evaluated before the array is assigned to $arrayList.

However, you have a bug in your getBoolean function. You need to return a boolean type value, not the string version of the boolean.

Code: (https://3v4l.org/AOdn3B)

$arrayList = [ [ 'uid' => '1234', 'nilai' => getBoolean (1) ] ];

function getBoolean ($value) {
    return (bool) $value;
}

echo json_encode ($arrayList);

Output:

[{"uid":"1234","nilai":true}]

---

p.s. I wouldn't personally bother to write a custom function for this. Just prepend (bool) directly to your array value.

$arrayList = [ [ 'uid' => 1234, 'nilai' => (bool) 1 ] ];

Then again if you have negative numbers or some other fringe case, use:

if ($value == 0) {
    return false; // boolean, not string
} else {
    return true; // boolean, not string
}