PHP array 的加法操作代码
2018-09-08 01:03
The + operator appends elements of remaining keys from the right handed array to the left handed, whereas duplicated keys are NOT overwritten.
今天 再次看 php manual的时候，才知道
复制代码 代码如下:
<?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:
复制代码 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。