使用键查找数组值

Question

我想使用密钥在数组中找到值.

像这样:

$array=('us'=>'United', 'ca'=>'canada');
$key='ca';

我怎么能拥有"加拿大"的价值？谢谢.

Answer 1

这很简单:

$array[$key];

Answer 2

看起来你正在编写PHP,在这种情况下你想要:

<?
$arr=array('us'=>'United', 'ca'=>'canada');
$key='ca';
echo $arr[$key];
?>

请注意,('us'=>'United', 'ca'=>'canada')需要在PHP中作为数组函数的参数.

大多数支持关联数组或字典的编程语言都arr['key']用于检索指定的项目'key'

例如:

红宝石

ruby-1.9.1-p378 > h = {'us' => 'USA', 'ca' => 'Canada' }
 => {"us"=>"USA", "ca"=>"Canada"} 
ruby-1.9.1-p378 > h['ca']
 => "Canada" 

蟒蛇

>>> h = {'us':'USA', 'ca':'Canada'}
>>> h['ca']
'Canada'

C#

class P
{
    static void Main()
    {
        var d = new System.Collections.Generic.Dictionary<string, string> { {"us", "USA"}, {"ca", "Canada"}};
        System.Console.WriteLine(d["ca"]);
    }
}

LUA

t = {us='USA', ca='Canada'}
print(t['ca'])
print(t.ca) -- Lua's a little different with tables