Question

I have a multidimensional array that has some values that are strings, and some values that are numbers. When I convert the array into a JSON object, I get a result that looks like this:

"A" : "1", "B" : "Text", "C" : "3"

The goal is to have a JSON that looks like this

"A" : 1, "B" : "Text", "C" : 3

Before, I was accomplishing this by editing the JSON after it had been encoded:

$JSON = preg_replace('/"(-?\d+\.?\d*)"/', '$1', json_encode($array));

But that has been problematic for a whole bunch of reasons.

So, instead, before converting the array into a JSON with json_encode(), I’d like to step through all the values and make sure that if a value is a number, then they type for that value is changed from string to int.

I know I can set the type of a variable in PHP with the settype() command:

settype(int, $variable);

I think that I need to combine that with a command like array_walk(), but I don’t know how I would combine it in a way so that it does a test to only act on numbers.

Is it possible in PHP to hunt through a multidimensional array, find values containing only numbers, and convert them into an int type?

Answer 1

You can use the JSON_NUMERIC_CHECK option:

$array = array('A' => '1', 'B' => 'Text', 'C' => '3');
echo json_encode($array, JSON_NUMERIC_CHECK);

Or you can loop over the array:

$array = array('A' => '1', 'B' => 'Text', 'C' => '3');
foreach ($array as & $value) {
    if (is_string($value) && ctype_digit($value)) {
        $value = (int) $value;
    }
}
echo json_encode($array);

Edit: Just for posterity, the & turns $value into a reference (which points to the actual content of the array item), as opposed to just a variable with a value.