otnv

JavaScript Array 的使用方法和以前寫過的程式陣列比較不一樣
這是一個很好的插入陣列元素以及置換陣列元素的好方法，特此註記。

Definition and Usage
The splice() method is used to remove and add new elements to an array.

Syntax
arrayObject.splice(index,howmany,element1,.....,elementX)

Parameter
@index Required. Specify where to add/remove elements. Must be a number
@howmany Required Specify how many elements should be removed. Must be a number, but can be "0"
@element1 Optional. Specify a new element to add to the array
@elementX Optional. Several elements can be added

Example 1
In this example we will create an array and add an element to it:

<script type="text/javascript">

var arr = new Array(5);
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

document.write(arr + "<br />");
arr.splice(2,0,"Lene");
document.write(arr + "<br />");

</script>

The output of the code above will be:
Jani,Hege,Stale,Kai Jim,Borge
Jani,Hege,Lene,Stale,Kai Jim,Borge


Example 2
In this example we will remove the element at index 2 ("Stale"), and add a new element ("Tove") there instead:

<script type="text/javascript">

var arr = new Array(5);
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

document.write(arr + "<br />");
arr.splice(2,1,"Tove");
document.write(arr);

</script>

The output of the code above will be:
Jani,Hege,Stale,Kai Jim,Borge
Jani,Hege,Tove,Kai Jim,Borge


Example 3
In this example we will remove three elements starting at index 2 ("Stale"), and add a new element ("Tove") there instead:

<script type="text/javascript">

var arr = new Array(5);
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

document.write(arr + "<br />");
arr.splice(2,3,"Tove");
document.write(arr);

</script>

The output of the code above will be:
Jani,Hege,Stale,Kai Jim,Borge
Jani,Hege,Tove

Source: http://www.w3schools.com/jsref/jsref_splice.asp