我如何将逗号分隔列表转换为方括号数组

Question

I have this variable $csv = '3,6,7,8'; that i need to convert to a square bracketed array of the form $csv_array = [3,6,7,8];

If i explode the csv like $new_array=explode(",",$csv);,it does not give me the array i want.

This is a running example http://3v4l.org/kYC0g

The code

$csv = '3,6,7,8';
$new_csv = '['.$csv.']';

if(is_array($new_csv)){
echo 'true';
}
else{
echo 'false';
//this is false
}

echo '<br/>';
$new_array=explode(",",$csv);

print_r($new_array);
//not what i am looking for

echo '<br/>';

print_r($new_csv);

echo '<br/>';

echo $new_csv;

Answer 1

As stated by a fellow stacker

RichardBernards - The two 'types' of array are exactly the same in PHP. If you are looking for JSON

An example of using JSON to achieve what it is you require:

To encode:

$csv = '3,6,7,8';
$array = explode(",", $csv);
$json = json_encode($array);

echo $json;

To decode $csv into the normal array you provided it:

$decoded = json_decode($json, true);
var_dump($decoded);

And then to return it to its original format:

$csv = implode(',', $decoded);

See json_encode() for more information, and also see it's opposite json_decode()

Keep in mind that JSON is literally a string and is not compatible associatively in PHP until it is decoded using the json_decode() function mentioned above. With that being said, replacing true with false in the example above would create an object array and multi-dimensional arrays would require them to be referenced differently, e.g. $array->result.

It would also be worth bringing to your attention the beauty of the predefined CSV functions within PHP