Question

I sometimes have variables that might not be set and I would like to use a default parameter instead. Like here:

if ($p == "a") doSomething();

If $p is not defined PHP throws Notice: Undefined variable. To avoid this I often I used this construct in such a case:

$p = (isset($p) ? $p : "");

But that is ugly if you have to use it a lot. So I wrote a function for it:

function getIfSet(&$value, $default = '')
{
    return isset($value) ? $value : $default;
}

// Example
if (getIfSet($p) == "a") doSomething();

I wonder if there is a PHP function for this or how you solve this.

Answer 1

I tried to make renocor’s answer more clean and OOP when I came up with this solution:

class NiceArray implements ArrayAccess {
    protected $array;

    public function __construct(&$array) {
        $this->array =& $array;
    }

    public function offsetExists($offset) {
        return true;
    }

    public function offsetGet($offset) {
        if (isset($this->array[$offset]))
        {
            return $this->array[$offset];
        }
        else
        {
            return null;
        }
    }

    public function offsetSet($offset, $value) {
        $this->array[$offset] = $value;
    }

    public function offsetUnset($offset) {
        unset($this->array[$offset]);
    }
}

Usage:

$get = new NiceArray($_GET);
if ($get['p'] == "a") doSomething();

I know the class is kind of big but this way you still have an array and you can easily use it for every array you want. You do not need to change any code you may had before. You can still access and change the data. It will even change the original array.