How to make a php line of code compatible with php5.3 version?

Question

It must be a simple question but would like to know, how I can write below for php 5.3 compatible?

 $parts = explode(' ', $data['start-line'], 3);
$version = isset($parts[2]) ? explode('/', $parts[2])[1] : '1.1';

Like in second line I am getting unexpected [ error because of php 5.3 is not allowed to directly write lines like explode('/',$parts[2])[1] - as [1] is not allowed to write directly in php 5.3 so either I have to write like $exp = explode('/',$parts[2]); $exp[2] am I right?

Is it following right?

$parts = explode(' ', $data['start-line'], 3);
$exp = explode('/', $parts[2]);
$version = isset($parts[2]) ? $exp[1] : '1.1';

Second Issue Second line issue on the following code as well:

  if (!is_array($result[$key])) {
            $result[$key] = [$result[$key]];

How I can write $result[$key] = [$result[$key]] line compatible with php 5.3? As above line returning unexpected [ error as well.

Second Issue Whole code:

function parse_query($str, $urlEncoding = true)

{ $result = array();

if ($str === '') {
    return $result;
}

if ($urlEncoding === true) {
    $decoder = function ($value) {
        return rawurldecode(str_replace('+', ' ', $value));
    };
} elseif ($urlEncoding === PHP_QUERY_RFC3986) {
    $decoder = 'rawurldecode';
} elseif ($urlEncoding === PHP_QUERY_RFC1738) {
    $decoder = 'urldecode';
} else {
    $decoder = function ($str) { return $str; };
}

foreach (explode('&', $str) as $kvp) {
    $parts = explode('=', $kvp, 2);
    $key = $decoder($parts[0]);
    $value = isset($parts[1]) ? $decoder($parts[1]) : null;
    if (!isset($result[$key])) {
        $result[$key] = $value;
    } else {
        if (!is_array($result[$key])) {
            $result[$key] = [$result[$key]];
        }
        $result[$key][] = $value;
    }
}

return $result;

Thanks please explain to me how I can interpret this line of code.

Answer 1

This should work in an identical way to the original code. The original code however doesn't do a good job of checking for errors. For example, you may want to check if $temp[1] is set, and then return it, otherwise, return "1.1". But, that's not what the original code did.

$parts = explode(' ', $data['start-line'], 3);
$version = call_user_func( function() use( $parts ){
    if ( isset( $parts[2] ) ) {
        $temp = explode( '/', $parts[2] );
        return $temp[1];
    }
    return "1.1";
});

I can accomplish the same thing below in a way that's probably easier to understand. The only difference with below is that the $temp variable lives in the same variable scope as possibly other variables. If you had another $temp variable defined, then the code below could have unintended side effects. The code above takes some additional steps to ensure side effects are not possible, given that I don't know what the surrounding code is.

$parts = explode(' ', $data['start-line'], 3);
if ( isset( $parts[2] ) ) {
    $temp = explode( '/', $parts[2] );
    $version = $temp[1];
} else {
    $version = "1.1";
}