"splice" - JS method to add/remove array elements

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	Description
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

 

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Example

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

 

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Example

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

 

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Example

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

Ref Link : http://www.w3schools.com/jsref/jsref_splice.asp

JavaScript function equivalent to Arraygetindex

 

This js function will find the index of an array element with the given value in an array.
for Example you are having an array like

var mnuArray = new Array("Groups","Services","Applications");

And want to know the index/position of and element in an array, then
Ex. you can call mnuArray.findIndex("Services");
This will return "1″.

 

This will be helpful if you are having a large size array/the elements are unknown which you have populated from an dB

 

Array.prototype.findIndex = function(value){
var ctr = "";
for (var i=0; i < this.length; i++) {
// use === to check for Matches. ie., identical (===), ;
if (this[i] == value) {
return i;
}
}
return ctr;
};

And advanced version of this function is,
If you want to do the same in the case of multidimensional arrays
then use the following

 

Array.prototype.findIndexByCol = function(value,cIdx){
var ctr = "";
for (var i=0; i < this.length; i++) {
// use === to check for Matches. ie., identical (===), ;
if (this[i][cIdx] == value) {
//alert(this[i][cIdx]+"===="+value);
return i;
}
}
return ctr;
};