基础知识积累

1.array_merge()     与     数组相加的   区别

$array1 = array("color" => "red", 2=>2, 3=>4);
$array2 = array(2=>"a", "b", "color" => "green", "shape" => "trapezoid", 2=>4);
$result = array_merge($array1, $array2);
print_r($result);

$array1 = array("color" => "red", 2=>2, 3=>4);
$array2 = array("a", "b", "color" => "green", "shape" => "trapezoid", 2=>4);
print_r($array1+$array2);

2. 对象赋值

class A{

}

$a = new A;

$b = $a;

$c = clone $a;