将匹配的元素集合缩减为给定位置之前的所有元素。这个元素在匹配元素集合中的位置变为0，而长度变成1。

返回值：jQuery

参数：

• pos (Number): 把集合缩减为这个位置之下的所有元素

示例：

$("p").lt(1)

HTML 代码:

<p>This is just a test.</p><p>So is this</p>

结果:

[ <p>This is just a test.</p> ]

lt( pos )

Reduce the set of matched elements to all elements before a given position. The position of the element in the set of matched elements starts at 0 and goes to length - 1.

Return value: jQuery
Parameters:

• pos (Number): Reduce the set to all elements below this position.

Example:

 $("p").lt(1)  

 <p>This is just a test.</p><p>So is this</p>  

Result:

 [ <p>This is just a test.</p> ]