Find out if a function was called with a parameter default value

A function can have optional arguments. They are determined to give it a default value defined. For example

function test ($key, $value = null)

But how can we differentiate whether this function is called with only one parameter, or if it is called using two but the second is equal to the default?
The solution is nested but not difficult... We simply need to find how many arguments were passed to the function when called


Function test ($key, $value = null)
{
If (func_num_args ()> 1) {
Echo '$value is sent';
}
}

test('1', null);
test('1');

Flexible parameters, hard returns

When programming a function, or a method of a class, always is the best thing to be able to receive any type of parameter. Analyze if is more comfortable to mix two parameters in one, using an Array, or if a data can be of several types. All these things it is necessary to have them in account so that soon it is less difficult to work with which already it is done. Another thing that we must try is always to return the same data type, even if it were not possible to be made what it was expected, then if an Array is due to return, but was an error we can return an empty Array instead of false or null. A simple example of this



function select($nombre, $valores = array(), $seleccionado = '', $atributos = array())
{
if (!is_array($valores) || count($valores) == 0)
{
return '';
}

if (is_string($nombre))
{
if (is_array($atributos))
{
$atributos['name'] = $nombre;
} else
{
$atributos .= ' name="' . htmlentities($nombre) . '"';
}
}
$out = '<select';
if (is_array($atributos))
{
foreach ($atributos as $atributo_nombre => $atributo_valor)
{
$out .= ' ' . $atributo_nombre . '="' . htmlentities($atributo_valor) . '"';
}
} else
{
$out .= ' ' . $atributos;
}
$out .= '>';
foreach ((array)$valores as $valor_clave => $valor_etiqueta)
{
$out .= '<option value="' . htmlentities($valor_clave) . '"' . ($valor_clave == $seleccionado || (is_array($seleccionado) && in_array($valor_clave,$seleccionado)) ? 'selected="selected"' : '') . '>' . htmlentities($valor_etiqueta) . '</option>';
}
return $out . '</select>';
}

echo select('select',array('a' => 'A', 'b' => 'B','c' => 'C','d' => 'D'),array('a'),array('id' => 'select', 'multiple' => 'multiple'));
echo PHP_EOL;
echo select('select',array('a' => 'A', 'b' => 'B','c' => 'C','d' => 'D'),'a','id="select"');
echo PHP_EOL;
echo select('select');



Avoid double functions calls

I was thinking that I can take any function and optimize it by storing results already calculated in a temporary variable.
Therefore, I took common mathematical formula, the “quadratic one” that is used to obtain the roots of a polynomial of degree two, and began to prove forms to improve it.

Several were the attempts, and the conclusion at which I arrived is that although he is better to store results of calls of functions, is not the best thing to keep it from operating simpler like the multiplication.

View example