Your arrays on steroids

就如我们上面提到的，把你的Array中的elements当成相同的类型使用相同的属性和函数是很通用(Common,不知该翻译成通用还是庸俗)的。让我们看看怎么样利用我们新的马力强劲的Arrays的迭代功能吧。

依照标准找到一个element。

<script> 
function findEmployeeById(emp_id){ 
var listBox = $(’lstEmployees’) 
var options = listBox.getElementsByTagName(’option’); 
options = $A(options); 
var opt = options.find( function(employee){ 
return (employee.value == emp_id); 
}); 
alert(opt.innerHTML); //displays the employee name 
} 
</script> 
<select id="lstEmployees" size="10" > 
<option value="5">Buchanan, Steven</option> 
<option value="8">Callahan, Laura</option> 
<option value="1">Davolio, Nancy</option> 
</select> 
<input type="button" value="Find Laura" onclick="findEmployeeById(8);" > 

现在我们再下一城，看看如何过滤一个Array中的元素，从每个元素中得到我们想要的成员。

<script> 
function showLocalLinks(paragraph){ 
paragraph = $(paragraph); 
var links = $A(paragraph.getElementsByTagName(’a’)); 
//find links that do not start with ’http’ 
var localLinks = links.findAll( function(link){ 
var start = link.href.substring(0,4); 
return start !=’http’; 
}); 
//now the link texts 
var texts = localLinks.pluck(’innerHTML’); 
//get them in a single string 
var result = texts.inspect(); 
alert(result); 
} 
</script> 
<p id="someText"> 
This <a href="http://othersite.com/page.html">text</a> has 
a <a href="#localAnchor">lot</a> of 
<a href="#otherAnchor">links</a>. Some are 
<a href="http://wherever.com/page.html">external</a> 
and some are <a href="#someAnchor">local</a> 
</p> 
<input type=button value="Find Local Links" onclick="showLocalLinks(’someText’)"> 

上面的代码仅仅是一点小小的实践让人爱上这种语法。请参看 Enumerable和Array的所有函数