Find out how to add an item to an array using JavaScript Splice. The Arraysplice method is an inbuilt method in JavaScript which is used to modify the contents of an array by removing the existing elements andor by adding new elements.

JavaScript Splice Syntax

Here is the Splice method syntax.

arraysplicestart count items

Splice methods parameters Description

start this is the position where an item will insert. This is required.

count how many items you want to remove. If it is set to 0 no item will remove. This is optional.

items commaseparated list of items you want insert at a specific position.

Note Before adding an element to an array we must know about its index position. Each array start with an index 0.

Insert an item at the beginning of an array using Splice

We will insert an item at the first position ie index 0.

var array two three four arraysplice0 0 one the result array is one two three four

Insert an item at a specific index of an array using Splice

We want to insert an item at 2nd position ie index 1.

var array red green yellow blue arraysplice1 0 pink the result array is red pink green yellow blue

Insert multiple items in an array

Now we want to insert multiple colors in the above array.

var array red green yellow blue arraysplice1 0 pink gray orange the result array is red pink gray orange green yellow blue

Start is greater than the length of an array

If the start index of the inserting item is greater than the length of an array. The start will be set to the length of the array.

var array red green yellow arraysplice5 0 orange the result array is red green yellow orange

Start is negative

If negative it will begin that many elements from the end of the array with origin 1 meaning n is the index of the nth last element and is therefore equivalent to the index of arraylength n

var array red green yellow arraysplice1 0 orange the result array is red green orange yellow

Reference developermozillaorg

Conclusion

We learned about various methods of inserting an item in an array using Splice method. I hope you enjoyed this post.

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