PHP functions use note points SSD usage precautions ID Use precautions etc use note things

Attention:

1, php function parameters, when using the default parameters, any default parameters must be placed on the right side of any non-default parameters, otherwise the function will not work as expected.

2. PHP cannot return multiple values, but can achieve the same effect by returning an array

function Getarr () {

return Array (+/-);

}

List ($a, $b, $c) =getarr ();

3, return a reference from the function, you must use the operator when declaring and assigning return values to a variable &

Global $arr;

$arr =array (3);

Function & Return_reference () {

Global $arr;

Print_r ($arr);

return $arr;

}

$newref =& return_reference ();

$newref [0]=4;

$newref =& return_reference ();

4. Anonymous function

Class cart{

Const price_butter=1.00;

Const price_milk=3.00;

Const price_egg=6.95;

Protected $products =array ();

Public Function getquantity ($product) {

return isset ($this->products[$product])? $this->products[$product]:false;

}

Public Function Gettotal ($tax) {

$total =0.00;

$callback =function ($quantity, $product) use ($tax,& $total) {

$pricePerItem =constant (__class__. "::P rice_". Strtoupper ($product));

$total + = ($pricePerItem * $quantity) * ($tax +1.0);

}

Array_walk ( $this->products, $callback);

Return round ($total, 2);

}

}

$mycart =new Cart;

$mycart->add (' Butter ', 1);

$mycart->add (' Milk ', 3);

$mycart->add (' eggs ', 6);

echo $mycart->gettotal (0.05);

The above introduces the use of PHP function note points, including the use of attention, PHP content, I hope that the PHP tutorial interested in a friend helpful.

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