PHParray的加法操作代码_PHP

$a = array("a" => "apple", "b" => "banana"); 
$b = array("a" => "pear", "b" => "strawberry", "c" => "cherry"); 
$c = $a + $b; // Union of $a and $b 
echo "Union of \$a and \$b: \n"; 
var_dump($c); 
$c = $b + $a; // Union of $b and $a 
echo "Union of \$b and \$a: \n"; 
var_dump($c); 
?> 
 
 
When executed, this script will print the following: 
Union of $a and $b: 
 代码如下:

array(3) { 
["a"]=> 
string(5) "apple" 
["b"]=> 
string(6) "banana" 
["c"]=> 
string(6) "cherry" 
} 
Union of $b and $a: 
array(3) { 
["a"]=> 
string(4) "pear" 
["b"]=> 
string(10) "strawberry" 
["c"]=> 
string(6) "cherry" 
} 
 
原来，我的理解就是。直接把$b中的元素直接复制到$a中。 
我错了。