jQuery in Action
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CHAPTER 2
Creating the wrapped element set
of the wrapped elements. We can also subset the wrapped set, based on the posi-
tion of the elements within the set. Let's see which methods allow us to do that.
tion of the elements within the set. Let's see which methods allow us to do that.
Obtaining subsets of the wrapped set
Sometimes we may wish to obtain a subset of the wrapped set, based on the posi-
tion of elements within the set. jQuery provides a method to do that named
tion of elements within the set. jQuery provides a method to do that named
slice()
. This command creates and returns a new set from any contiguous por-
tion, or a slice, of an original wrapped set. The syntax for this command follows:
If we want to obtain a wrapped set that contains a single element from another
set, based on its position in the original set, we could employ the
set, based on its position in the original set, we could employ the
slice()
method,
passing the zero-based position of the element within the wrapped set. For exam-
ple, to obtain the third element, we write
ple, to obtain the third element, we write
$('*').slice(2,3);
This statement selects all elements on the page and then generates a new set con-
taining the third element in the matched set.
taining the third element in the matched set.
Note that this is different from
$('*').get(2)
, which returns the third element
in the wrapped set, not a wrapped set containing the element.
Therefore, a statement such as
$('*').slice(0,4);
selects all elements on the page and then creates a set containing the first four
elements.
elements.
To grab elements from the end of the wrapped set, the statement
$('*').slice(4);
Command syntax: slice
slice(begin,end)
Creates and returns a new wrapped set containing a contiguous portion of the matched set.
Parameters
begin
(Number) The zero-based position of the first element to be included in the
returned slice.
returned slice.
end
(Number) The optional zero-based index of the first element not to be included in
the returned slice, or one position beyond the last element to be included. If omit-
ted, the slice extends to the end of the set.
the returned slice, or one position beyond the last element to be included. If omit-
ted, the slice extends to the end of the set.
Returns
The newly created wrapped set.
The newly created wrapped set.