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The splice() method
adds and/or removes elements from an array at any position in the array, and returns a new array of elements removed..
The complete syntax for splice() is:
removedElements = arrayName.splice(index, count, newelement1, newelement2,...,newelementn)
The first argument, index, should be considered mandatory. As we will see later, it may be omitted but it is not good form:
Visually, we can represent the splice() method in this way:
Let's bring our example array, myArray, back into use:
myArray = [0,"cat",true];, or
myArray = new Array(0,"cat",true);
We want to remove the second element, "cat", from the array, ending up with an array of only two elements:
[0,true]
Using splice(), we can execute this statement:
myArray.splice(1,1);
In plain English, the statement reads:
"Go to index 1 (second element) of myArray and remove 1 element."
If we also want to store this removed element to a variable, myPet, for later use, the syntax would be:
removedElements = myArray.splice(1,1); myPet = removedElements[0];
Remember that splice() always returns an array of elements. If only one element is removed, then an array with a single element is returned. In our example, removedElements looks like this:
["cat"]
To assign any of the removed elements to variables, we must grab them from the returned array, as we do with myPet, above.
What if we wanted to insert elements into myArray, instead of removing them? For example, let's insert two new string elements, "dog" and "mouse" after the "cat" element. Our syntax would be:
myArray.splice(2,0,"dog","mouse");
Meaning:
"Go to index 2 (third element) of myArray. Do not remove any elements (0). Insert the elements "dog" and "mouse" at this position."
After statement execution myArray would look like this:
[0,"cat","dog","mouse",true]
We can also replace elements in an array using splice() by removing and inserting elements with a single statement. To get rid of the pesky "cat" element, replacing it with "dog", our splice() method takes this form:
myOldPet = myArray.splice(1,1,"dog");
That is, to say:
"Go to index 1 (second element) of myArray. Remove one element at this position (1). Now insert the element "dog" at this position. Assign the removed element to the myOldPet array."
myArray would then look like this:
[0,"dog",true]
Now, how can we achieve the same functionality of the three examples above without the splice() method? That is, how can we do it in Explorer?.
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Created: May 16, 2000
Revised: May 16, 2000
URL: http://www.webreference.com/dhtml/column33/2.html
