php 使用键查找数组值
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Find array value using key
提问by JEagle
I would like to find the value in an array using the key.
我想使用键在数组中找到值。
like this:
像这样：
$array=('us'=>'United', 'ca'=>'canada');
$key='ca';
How can i have the value 'canada'? thanks.
我怎么能拥有“加拿大”的价值？谢谢。
回答by HoLyVieR
It's as simple as this :
就这么简单：
$array[$key];
回答by Mark Rushakoff
It looks like you're writing PHP, in which case you want:
看起来您正在编写 PHP，在这种情况下，您需要：
<?
$arr=array('us'=>'United', 'ca'=>'canada');
$key='ca';
echo $arr[$key];
?>
Notice that the ('us'=>'United', 'ca'=>'canada')needs to be a parameter to the array functionin PHP.
请注意，('us'=>'United', 'ca'=>'canada')需要是PHP 中数组函数的参数。
Most programming languages that support associative arrays or dictionaries use arr['key']to retrieve the item specified by 'key'
大多数支持关联数组或字典的编程语言arr['key']用于检索由'key'
For instance:
例如：
Ruby
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"
Python
Python
>>> h = {'us':'USA', 'ca':'Canada'}
>>> h['ca']
'Canada'
C#
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
路亚
t = {us='USA', ca='Canada'}
print(t['ca'])
print(t.ca) -- Lua's a little different with tables
