php 数组的+号运算符

+ 运算符把右边的数组附加到左边的数组后面，但是重复的键值不会被覆盖。

<?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);

?>

执行后，此脚本会显示：

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Union of $a and $b:

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"

} ?>